IB/qib: Remove unnecessary read of PCI_CAP_ID_EXP

The PCIE capability offset is saved during PCI bus walking.  It will
remove an unnecessary search in the PCI configuration space if this
value is referenced instead of reacquiring it.
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Acked-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/qib/qib_pcie.c

@@ -255,7 +255,7 @@ int qib_pcie_params(struct qib_devdata *dd, u32 minw, u32 *nent,
 	u16 linkstat, speed;
 	int pos = 0, pose, ret = 1;
 
-	pose = pci_find_capability(dd->pcidev, PCI_CAP_ID_EXP);
+	pose = pci_pcie_cap(dd->pcidev);
 	if (!pose) {
 		qib_dev_err(dd, "Can't find PCI Express capability!\n");
 		/* set up something... */
@@ -509,7 +509,7 @@ static int qib_tune_pcie_coalesce(struct qib_devdata *dd)
 		qib_devinfo(dd->pcidev, "Parent not root\n");
 		return 1;
 	}
-	ppos = pci_find_capability(parent, PCI_CAP_ID_EXP);
+	ppos = pci_pcie_cap(parent);
 	if (!ppos)
 		return 1;
 	if (parent->vendor != 0x8086)
@@ -578,14 +578,14 @@ static int qib_tune_pcie_caps(struct qib_devdata *dd)
 		qib_devinfo(dd->pcidev, "Parent not root\n");
 		goto bail;
 	}
-	ppos = pci_find_capability(parent, PCI_CAP_ID_EXP);
+	ppos = pci_pcie_cap(parent);
 	if (ppos) {
 		pci_read_config_word(parent, ppos + PCI_EXP_DEVCAP, &pcaps);
 		pci_read_config_word(parent, ppos + PCI_EXP_DEVCTL, &pctl);
 	} else
 		goto bail;
 	/* Find out supported and configured values for endpoint (us) */
-	epos = pci_find_capability(dd->pcidev, PCI_CAP_ID_EXP);
+	epos = pci_pcie_cap(dd->pcidev);
 	if (epos) {
 		pci_read_config_word(dd->pcidev, epos + PCI_EXP_DEVCAP, &ecaps);
 		pci_read_config_word(dd->pcidev, epos + PCI_EXP_DEVCTL, &ectl);