rapidio: remove unnecessary use of list iterator

rapidio: remove unnecessary use of list iterator

req->map is set in the valid case and always equals 'map' if the break was
hit.  It therefore is unnecessary to use the list iterator variable and
the use of 'map' can be replaced with req->map.

This is done in preparation to limit the scope of a list iterator to the
list traversal loop [1].

Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/
Link: https://lkml.kernel.org/r/20220319203344.2547702-1-jakobkoschel@gmail.com
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "Brian Johannesmeyer" <bjohannesmeyer@gmail.com>
Cc: Cristiano Giuffrida <c.giuffrida@vu.nl>
Cc: "Bos, H.J." <h.j.bos@vu.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>