f2fs: prevent writing without fallocate() for pinned files

f2fs: prevent writing without fallocate() for pinned files

In a case writing without fallocate(), we can't guarantee it's allocated
in the conventional area for zoned stroage. To make it consistent across
storage devices, we disallow it regardless of storage device types.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>