ceph: fix flaky OSD on PVC unit test
ceph: fix flaky OSD on PVC unit test

This was a race condition where the test would sometimes finish before a
deferred watcher.Stop() command was called and sometimes would not.

Signed-off-by: Blaine Gardner <135b86f2968bdbcc730c10d8ababd343bb675986@redhat.com>

rook/rook,rook/nfs,rook/rook,rook/nfs,rook/nfs,rook/rook,rook/rook,rook/rook