ext4: avoid remove directory when directory is corrupted

Now if check directoy entry is corrupted, ext4_empty_dir may return true
then directory will be removed when file system mounted with "errors=continue".
In order not to make things worse just return false when directory is corrupted.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220622090223.682234-1-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>