NFSv4: Don't add a new lock on an interrupted wait for LOCK

If the wait for a LOCK operation is interrupted, and then the file is
closed, the locks cleanup code will assume that no new locks will be added
to the inode after it has completed.  We already have a mechanism to detect
if there was signal, so let's use that to avoid recreating the local lock
once the RPC completes.  Also skip re-sending the LOCK operation for the
various error cases if we were signaled.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
[Trond: Fix inverted test of locks_lock_inode_wait()]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>