NFSD: Reserve adequate space for LOCKT operation

After tightening the OP_LOCKT reply size estimate, we can get warnings
like:

[11512.783519] RPC request reserved 124 but used 152
[11512.813624] RPC request reserved 108 but used 136

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 7e4df80..382c1fd0 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1941,12 +1941,12 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 		} else
 			max_reply += nfsd4_max_reply(argp->rqstp, op);
 		/*
-		 * OP_LOCK may return a conflicting lock.  (Special case
-		 * because it will just skip encoding this if it runs
-		 * out of xdr buffer space, and it is the only operation
-		 * that behaves this way.)
+		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
+		 * (Special case because it will just skip encoding this
+		 * if it runs out of xdr buffer space, and it is the only
+		 * operation that behaves this way.)
 		 */
-		if (op->opnum == OP_LOCK)
+		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
 			max_reply += NFS4_OPAQUE_LIMIT;
 
 		if (op->status) {