UPSTREAM: f2fs: prevent atomic file from being dirtied before commit

Keep atomic file clean while updating and make it dirtied during commit
in order to avoid unnecessary and excessive inode updates in the previous
fix.

Fixes: 4bf78322 ("f2fs: mark inode dirty for FI_ATOMIC_COMMITTED flag")
Change-Id: Ia65957ef9632fb8e3664d097ecd0c3af6a768802
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit fccaa81d)