ntfs: avoid unnecessary padding in uapi structure

Building the uapi headers with -Wpadded shows a warning that
may indicate an incompatibility:

./usr/include/linux/ntfs.h:91:1: error: padding struct size to alignment boundary with 4 bytes [-Werror=padded]

This is relatively harmless here as the 64-bit members force natural
alignment, so this is not a problem for compat ioctls, and I checked
that the padding word is still initialized by means of using kvzalloc()
to allocate it, but it's better to avoid the padding out of
principle.

Change the reserved member to use a 64-bit type so the name field
starts after the structure and all padding is explicit.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Baolin Liu <liubaolin@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

include/uapi/linux/ntfs.h

@@ -86,7 +86,7 @@ struct ntfs_stream_entry {
 	__aligned_u64 alloc_size;
 	__u32 name_len;
 	__u32 name_offset;
-	__u32 reserved;
+	__aligned_u64 reserved;
 	__u8 name[];
 };