[SCSI] mpt2sas: use correct pci_resource_flag for comparison

This patch replaces incorrect base address space flag with correct IO
resource flag.  Also, performs check of memory resource to validate
resource before using.

Signed-off-by: Richard A Lary <rlary@linux.vnet.ibm.com>
Acked-by: "Desai, Kashyap" <Kashyap.Desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>