BACKPORT: f2fs: synchronize atomic write aborts

To fix a race condition between atomic write aborts, I use the inode
lock and make COW inode to be re-usable thoroughout the whole
atomic file inode lifetime.

Bug: 298879042
Reported-by:  <syzbot+823000d23b3400619f7c@syzkaller.appspotmail.com>
Fixes: 3db1de0e ("f2fs: change the current atomic write way")
Change-Id: I50fce037ad57deded523d7226f17e8086f9d8c17
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit fbff945c)
Signed-off-by: zhoudan8 <zhoudan8@xiaomi.com>