NFSv4.1: Clean up nfs41_sequence_done

Move the test for res->sr_slot == NULL out of the nfs41_sequence_free_slot
helper and into the main function for efficiency.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 493e9cc..42da6af 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -559,15 +559,10 @@
 {
 	struct nfs4_session *session;
 	struct nfs4_slot_table *tbl;
+	struct nfs4_slot *slot = res->sr_slot;
 	bool send_new_highest_used_slotid = false;
 
-	if (!res->sr_slot) {
-		/* just wake up the next guy waiting since
-		 * we may have not consumed a slot after all */
-		dprintk("%s: No slot\n", __func__);
-		return;
-	}
-	tbl = res->sr_slot->table;
+	tbl = slot->table;
 	session = tbl->session;
 
 	spin_lock(&tbl->slot_tbl_lock);
@@ -577,11 +572,11 @@
 	if (tbl->highest_used_slotid > tbl->target_highest_slotid)
 		send_new_highest_used_slotid = true;
 
-	if (nfs41_wake_and_assign_slot(tbl, res->sr_slot)) {
+	if (nfs41_wake_and_assign_slot(tbl, slot)) {
 		send_new_highest_used_slotid = false;
 		goto out_unlock;
 	}
-	nfs4_free_slot(tbl, res->sr_slot);
+	nfs4_free_slot(tbl, slot);
 
 	if (tbl->highest_used_slotid != NFS4_NO_SLOT)
 		send_new_highest_used_slotid = false;
@@ -595,16 +590,17 @@
 int nfs41_sequence_done(struct rpc_task *task, struct nfs4_sequence_res *res)
 {
 	struct nfs4_session *session;
-	struct nfs4_slot *slot;
+	struct nfs4_slot *slot = res->sr_slot;
 	struct nfs_client *clp;
 	bool interrupted = false;
 	int ret = 1;
 
+	if (slot == NULL)
+		goto out_noaction;
 	/* don't increment the sequence number if the task wasn't sent */
 	if (!RPC_WAS_SENT(task))
 		goto out;
 
-	slot = res->sr_slot;
 	session = slot->table->session;
 
 	if (slot->interrupted) {
@@ -679,6 +675,7 @@
 	/* The session may be reset by one of the error handlers. */
 	dprintk("%s: Error %d free the slot \n", __func__, res->sr_status);
 	nfs41_sequence_free_slot(res);
+out_noaction:
 	return ret;
 retry_nowait:
 	if (rpc_restart_call_prepare(task)) {