ksmbd: remove setattr preparations in set_file_basic_info()

Permission checking and copying over ownership information is the task
of the underlying filesystem not ksmbd. The order is also wrong here.
This modifies the inode before notify_change(). If notify_change() fails
this will have changed ownership nonetheless. All of this is unnecessary
though since the underlying filesystem's ->setattr handler will do all
this (if required) by itself.

Cc: Steve French <stfrench@microsoft.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>