ext4: remove unused buddy_loaded in ext4_mb_seq_groups_show

We can just first call ext4_mb_unload_buddy, then copy information from
ext4_group_info. So remove this unused value.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240118042557.380058-1-yangerkun@huawei.com


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