ext4: no need to add inode to orphan list during hole punch

While performing punch hole for an inode, i_disksize is not changed.
So, there is no need to add the inode to orphan list.

Signed-off-by: Ashish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>