rapidio: return an error code only as a constant in two functions

* Return an error code without storing it in an intermediate variable.

* Delete the label "out" and local variable "rc" which became unnecessary
  with this refactoring.

Link: http://lkml.kernel.org/r/8db441e1-c227-64e7-4747-095da63d7a2e@users.sourceforge.net


Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>