f2fs: update multi-dev metadata in resize_fs

Multi-device metadata should be updated in resize_fs as well.

Also, we check that the new FS size still reaches the last device.

Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>