UPSTREAM: exfat: fix file being changed by unaligned direct write

Unaligned direct writes are invalid and should return an error
without making any changes, rather than extending ->valid_size
and then returning an error. Therefore, alignment checking is
required before extending ->valid_size.

Fixes: 11a347fb ("exfat: change to get file size from DataLength")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Co-developed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
(cherry picked from commit 2e94e5bb)
Change-Id: I39f3116f0930ef7fd31fd79f0f69ef3251e3b81b
Bug: 397325648
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Lee Jones <joneslee@google.com>