Clean them up because
```
/home/jenkins-build/build/workspace/ceph-pull-requests-arm64/src/test/librbd/exclusive_lock/test_mock_PreAcquireRequest.cc:47:26: error: unused variable 'TEST_COOKIE' [-Werror,-Wunused-const-variable]
static const std::string TEST_COOKIE("auto 123");
^
1 error generated.
```
Ref: https://jenkins.ceph.com/job/ceph-pull-requests-arm64/59242/consoleFull#-
5120798632a811ea2-3e7b-466b-84b4-
d13df7e35809
Signed-off-by: Rongqi Sun <sunrongqi@huawei.com>
using ::testing::StrEq;
using ::testing::WithArg;
-static const std::string TEST_COOKIE("auto 123");
-
class TestMockExclusiveLockPostAcquireRequest : public TestMockFixture {
public:
typedef PostAcquireRequest<MockTestImageCtx> MockPostAcquireRequest;
using ::testing::StrEq;
using ::testing::WithArg;
-static const std::string TEST_COOKIE("auto 123");
-
class TestMockExclusiveLockPreAcquireRequest : public TestMockFixture {
public:
typedef PreAcquireRequest<MockTestImageCtx> MockPreAcquireRequest;
using ::testing::StrEq;
using ::testing::WithArg;
-static const std::string TEST_COOKIE("auto 123");
-
class TestMockExclusiveLockPreReleaseRequest : public TestMockFixture {
public:
typedef ImageDispatch<MockTestImageCtx> MockImageDispatch;