f2fs: add f2fs_bug_on in __remove_discard_cmd

Recently, discard related codes have changed a lot, so add f2fs_bug_on to
detect potential bug.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
1 file changed