mds: Don't acquire replica object's versionlock

mds: Don't acquire replica object's versionlock

Both CInode and CDentry's versionlocks are of type LocalLock.
Acquiring LocalLock in replica object is useless and problematic.
For example, if two requests try acquiring a replica object's
versionlock, the first request succeeds, the second request
is added to wait queue. Later when the first request finishes,
MDCache::request_drop_foreign_locks() finds the lock's parent is
non-auth, it skips waking requests in the wait queue. So the
second request hangs.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>