ext4: make ext4_es_insert_extent() return void

Now ext4_es_insert_extent() never return error, so make it return void.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230424033846.4732-12-libaokun1@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>