ocfs2/cluster: dereferencing before checking in nst_seq_show()

In the original code, we dereferenced "nst" before checking that it was
non-NULL.  I moved the check forward and pulled the code in an indent
level.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/cluster/netdebug.c

@@ -133,13 +133,14 @@ static int nst_seq_show(struct seq_file *seq, void *v)
 
 	spin_lock(&o2net_debug_lock);
 	nst = next_nst(dummy_nst);
+	if (!nst)
+		goto out;
 
 	now = ktime_get();
 	sock = ktime_to_us(ktime_sub(now, nst->st_sock_time));
 	send = ktime_to_us(ktime_sub(now, nst->st_send_time));
 	status = ktime_to_us(ktime_sub(now, nst->st_status_time));
 
-	if (nst != NULL) {
 	/* get_task_comm isn't exported.  oh well. */
 	seq_printf(seq, "%p:\n"
 		   "  pid:          %lu\n"
@@ -161,8 +162,8 @@ static int nst_seq_show(struct seq_file *seq, void *v)
 		   (long long)sock,
 		   (long long)send,
 		   (long long)status);
-	}
 
+out:
 	spin_unlock(&o2net_debug_lock);
 
 	return 0;