ksmbd: remove ____ksmbd_align in ksmbd_server.h

None of structures needs the attribute.
So remove ____ksmbd_align in ksmbd_server.h.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>