[SCSI] qla2xxx: Correct resource_size_t usages.

Hmm, it looks like the conversion to resource_size_t usage
(3776541d8a46347a4924353a192c6ce4a3d04e2e) requires some additional
fixups to cleanup the structure-pointer castings used during IO mapped
accesses to the chip.

There's only a small number of locations, where the driver uses IO
mapped accesses to the hardware, the patch below should take care of
it without introducing to many structural changes to code flow.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>