mds: fix acquire_lock() calls in handle_client_open()
mds: fix acquire_lock() calls in handle_client_open()

We want to acquire_locks exactly once per path through the function.
Don't look at mdr->* yet if we haven't locked yet.

Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph,ajnelson/ceph