f2fs: maintain one time GC mode is enabled during whole zoned GC cycle

f2fs: maintain one time GC mode is enabled during whole zoned GC cycle

The current version missed setting one time GC for normal zoned GC
cycle. So, valid threshold control is not working. Need to fix it to
prevent excessive GC for zoned devices.

Fixes: e791d00bd06c ("f2fs: add valid block ratio not to do excessive GC for one time GC")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>