test: : do not increase ref when creating intrusive_ptr<CephContext>

test: : do not increase ref when creating intrusive_ptr<CephContext>

before this change, we increment the refcount when constructing
`cct` instrusive_ptr, but nobody owns this smart pointer. also,
`CephContext` 's constructor set its refcount to 1. so, when the
test finishes, the refcount is 1, and this leads to a leakage of
the `CephContext` instance. and LeakSanitizer points this out:
```
Indirect leak of 10880000 byte(s) in 1 object(s) allocated from:
    #0 0x558d341d837d in operator new(unsigned long) (/home/jenkins-build/build/workspace/ceph-pull-requests/build/bin/unittest_ipaddr+0x19b37d) (BuildId: 1b7e7e5abfc2b58ce2334712e4c00b2441c25870)
    #1 0x7fd74c957559 in __gnu_cxx::new_allocator<ceph::logging::ConcreteEntry>::allocate(unsigned long, void const*) /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/ext/new_allocator.h:127:27
    #2 0x7fd74c956933 in std::allocator<ceph::logging::ConcreteEntry>::allocate(unsigned long) /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/bits/allocator.h:185:32
    #3 0x7fd74c956933 in boost::circular_buffer<ceph::logging::ConcreteEntry, std::allocator<ceph::logging::ConcreteEntry> >::allocate(unsigned long) /opt/ceph/include/boost/circular_buffer/base.hpp:2396:39
    #4 0x7fd74c956690 in boost::circular_buffer<ceph::logging::ConcreteEntry, std::allocator<ceph::logging::ConcreteEntry> >::initialize_buffer(unsigned long) /opt/ceph/include/boost/circular_buffer/base.hpp:2494:18
    #5 0x7fd74c950562 in boost::circular_buffer<ceph::logging::ConcreteEntry, std::allocator<ceph::logging::ConcreteEntry> >::circular_buffer(unsigned long, std::allocator<ceph::logging::ConcreteEntry> const&) /opt/ceph/include/boost/circ
ular_buffer/base.hpp:1039:9
    #6 0x7fd74c9435b4 in ceph::logging::Log::Log(ceph::logging::SubsystemMap const*) /home/jenkins-build/build/workspace/ceph-pull-requests/src/log/Log.cc:53:5
    #7 0x7fd74bc1891d in ceph::common::CephContext::CephContext(unsigned int, ceph::common::CephContext::create_options const&) /home/jenkins-build/build/workspace/ceph-pull-requests/src/common/ceph_context.cc:729:16
    #8 0x7fd74bc178eb in ceph::common::CephContext::CephContext(unsigned int, code_environment_t, int) /home/jenkins-build/build/workspace/ceph-pull-requests/src/common/ceph_context.cc:697:5
    #9 0x558d341f97e9 in pick_address_filtering_Test::TestBody() /home/jenkins-build/build/workspace/ceph-pull-requests/src/test/test_ipaddr.cc:774:47
    #10 0x558d3430c4f6 in void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2605:10
    #11 0x558d342c3fc2 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2641:14
    #12 0x558d342749dc in testing::Test::Run() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2680:5
    #13 0x558d34276a12 in testing::TestInfo::Run() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2858:11
    #14 0x558d3427804b in testing::TestSuite::Run() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:3012:28
    #15 0x558d342954d8 in testing::internal::UnitTestImpl::RunAllTests() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:5723:44
    #16 0x558d34314d26 in bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2605:10
    #17 0x558d342ca932 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:2641:14
    #18 0x558d34294862 in testing::UnitTest::Run() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/src/gtest.cc:5306:10
    #19 0x558d34218d80 in RUN_ALL_TESTS() /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googletest/include/gtest/gtest.h:2486:46
    #20 0x558d34218d11 in main /home/jenkins-build/build/workspace/ceph-pull-requests/src/googletest/googlemock/src/gmock_main.cc:70:10
    #21 0x7fd749331d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
```

so, in this change, we do not increase the refcount when creating cct.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>