IB/mthca: 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.  Also, pci_is_pcie is a
better way of determining if the device is PCIE or not (as it uses the
same saved PCIE capability offset).
Signed-off-by: NJon Mason <jdmason@kudzu.us>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mthca/mthca_main.c

@@ -149,7 +149,7 @@ static int mthca_tune_pci(struct mthca_dev *mdev)
 	} else if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE))
 		mthca_info(mdev, "No PCI-X capability, not setting RBC.\n");
 
-	if (pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP)) {
+	if (pci_is_pcie(mdev->pdev)) {
 		if (pcie_set_readrq(mdev->pdev, 4096)) {
 			mthca_err(mdev, "Couldn't write PCI Express read request, "
 				"aborting.\n");

drivers/infiniband/hw/mthca/mthca_reset.c

@@ -113,7 +113,7 @@ int mthca_reset(struct mthca_dev *mdev)
 	}
 
 	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
-	hca_pcie_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_EXP);
+	hca_pcie_cap = pci_pcie_cap(mdev->pdev);
 
 	if (bridge) {
 		bridge_header = kmalloc(256, GFP_KERNEL);