ext4: remove redundant goto in ext4_ext_insert_extent()

If eh->eh_entries is smaller than eh->eh_max, the routine will
go to the "repeat" and then go to "has_space" directlly ,
since argument "depth" and "eh" are not even changed.

Therefore, goto "has_space" directly and remove redundant "repeat" tag.

Signed-off-by: Robin Dong <sanbai@taobao.com>