[XFS] Don't update mtime on rename source

As reported by Michael-John Turner XFS updates the mtime on the source
inode of a rename call in case it's a directory and changes the parent.

This doesn't make any sense, is not mentioned in the standards and not
performed by any other Linux filesystems so remove it.

SGI-PV: 983684

SGI-Modid: xfs-linux-melb:xfs-kern:31364a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NBarry Naujok <bnaujok@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

fs/xfs/xfs_rename.c

@@ -336,20 +336,16 @@ xfs_rename(
 		ASSERT(error != EEXIST);
 		if (error)
 			goto abort_return;
-		xfs_ichgtime(src_ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+	}
 
-	} else {
 	/*
 	 * We always want to hit the ctime on the source inode.
-		 * We do it in the if clause above for the 'new_parent &&
-		 * src_is_directory' case, and here we get all the other
-		 * cases.  This isn't strictly required by the standards
-		 * since the source inode isn't really being changed,
-		 * but old unix file systems did it and some incremental
-		 * backup programs won't work without it.
+	 *
+	 * This isn't strictly required by the standards since the source
+	 * inode isn't really being changed, but old unix file systems did
+	 * it and some incremental backup programs won't work without it.
 	 */
 	xfs_ichgtime(src_ip, XFS_ICHGTIME_CHG);
-	}
 
 	/*
 	 * Adjust the link count on src_dp.  This is necessary when