xfs: use swap() to make code cleaner

Use swap() in order to make code cleaner. Issue found by coccinelle.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/xfs_inode.c

@@ -564,8 +564,6 @@ xfs_lock_two_inodes(
 	struct xfs_inode	*ip1,
 	uint			ip1_mode)
 {
-	struct xfs_inode	*temp;
-	uint			mode_temp;
 	int			attempts = 0;
 	struct xfs_log_item	*lp;
 
@@ -578,12 +576,8 @@ xfs_lock_two_inodes(
 	ASSERT(ip0->i_ino != ip1->i_ino);
 
 	if (ip0->i_ino > ip1->i_ino) {
-		temp = ip0;
-		ip0 = ip1;
-		ip1 = temp;
-		mode_temp = ip0_mode;
-		ip0_mode = ip1_mode;
-		ip1_mode = mode_temp;
+		swap(ip0, ip1);
+		swap(ip0_mode, ip1_mode);
 	}
 
  again: