fs: rename "rename2" i_op to "rename"

Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/ext4/namei.c

@@ -3880,7 +3880,7 @@ const struct inode_operations ext4_dir_inode_operations = {
 	.rmdir		= ext4_rmdir,
 	.mknod		= ext4_mknod,
 	.tmpfile	= ext4_tmpfile,
-	.rename2	= ext4_rename2,
+	.rename		= ext4_rename2,
 	.setattr	= ext4_setattr,
 	.setxattr	= generic_setxattr,
 	.getxattr	= generic_getxattr,