RadosClient: Fixing potential lock leaks.

In lookup_pool and pool_delete, a lock is taken
before invoking wait_for_osdmap, but is not
released for the failure case of the call. Fixing the same.

Fixes: #9022
Signed-off-by: Pavan Rallabhandi <pavan.rallabhandi@sandisk.com>
Merge pull request #2220 from somnathr/wip-lock-leak-fix

RadosClient: Fixing potential lock leaks.

Backport: firefly
Reviewed-by: Sage Weil <sage@redhat.com>
Merge remote-tracking branch 'somnathr/wip-sd-filestore-optimization' into wip-sam-testing2

Conflicts:
	src/osd/OSD.cc
Merge remote-tracking branches 'origin/wip-8396', 'origin/wip-8625' and 'guangyy/wip-pg-splitting' into wip-sam-testing2

Conflicts:
	src/os/CollectionIndex.h