[SCSI] ips: PCI API cleanups

* pass Scsi_Host to ips_remove_device() via pci_set_drvdata(),
  allowing us to eliminate the ips_ha[] search loop and call
  ips_release() directly.

* call pci_{request,release}_regions() and eliminate individual
  request/release_[mem_]region() calls

* call pci_disable_device(), paired with pci_enable_device()

* s/0/NULL/ in a few places

* check ioremap() return value

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: "Salyzyn, Mark" <mark_salyzyn@adaptec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>