NFSv4: Fix a typo in nfs41_sequence_process

We want to compare the slot_id to the highest slot number advertised by the
server.

Fixes: 3be0f80b ("NFSv4.1: Fix up replays of interrupted requests")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4proc.c

@@ -780,7 +780,7 @@ static int nfs41_sequence_process(struct rpc_task *task,
 		 * The slot id we used was probably retired. Try again
 		 * using a different slot id.
 		 */
-		if (slot->seq_nr < slot->table->target_highest_slotid)
+		if (slot->slot_nr < slot->table->target_highest_slotid)
 			goto session_recover;
 		goto retry_nowait;
 	case -NFS4ERR_SEQ_MISORDERED: