cifs: Don't advance the I/O iterator before terminating subrequest

There's now no need to make sure subreq->io_iter is advanced to match
subreq->transferred before calling one of the netfs subrequest termination
functions as the check has been removed netfslib and the iterator is reset
prior to retrying a subreq.

Fixes: 3ee1a1fc

 ("cifs: Cut over to using netfslib")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Steve French <stfrench@microsoft.com>