NFS: Fix an RCU lock leak in nfs4_refresh_delegation_stateid()

A typo in nfs4_refresh_delegation_stateid() means we're leaking an
RCU lock, and always returning a value of 'false'. As the function
description states, we were always supposed to return 'true' if a
matching delegation was found.

Fixes: 12f275cd ("NFSv4: Retry CLOSE and DELEGRETURN on NFS4ERR_OLD_STATEID.")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/delegation.c

@@ -1191,7 +1191,7 @@ bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
 	if (delegation != NULL &&
 	    nfs4_stateid_match_other(dst, &delegation->stateid)) {
 		dst->seqid = delegation->stateid.seqid;
-		return ret;
+		ret = true;
 	}
 	rcu_read_unlock();
 out: