tests: test/mon/osd-pool-create.sh uses ceph-helpers.sh

tests: test/mon/osd-pool-create.sh uses ceph-helpers.sh

Use ceph-helpers.sh instead of  mon/mon-test-helpers.sh.

  * The expect_false() helper is replaced by a ! statement which is
    simpler and has the same effect.

  * modifying the .asok and .log names to match the ceph-helpers.sh
    conventions

  * trim the --public-addr argument from the run_mon call

  * add || return 1 after run_mon where missing

  * add || return 1 to all commands in TEST_no_pool_delete

Signed-off-by: Loic Dachary <ldachary@redhat.com>