IB/hfi1: Check return values from PCI config API calls

Ensure that return values from kernel PCI config access
API calls in HFI driver are checked and react properly if
they are not expected (i.e. not successful).

Reviewed-by: Jakub Byczkowski <jakub.byczkowski@intel.com>
Signed-off-by: Bartlomiej Dudek <bartlomiej.dudek@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>