f2fs: don't keep META_MAPPING pages used for moving verity file blocks

META_MAPPING is used to move blocks for both encrypted and verity files.
So the META_MAPPING invalidation condition in do_checkpoint() should
consider verity too, not just encrypt.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>