IB/qib: Use pci_dev->revision

The driver reads PCI revision ID from the PCI configuration register
while it's already stored by PCI subsystem in the revision field of
struct pci_dev.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/qib/qib_pcie.c

@@ -526,11 +526,8 @@ static int qib_tune_pcie_coalesce(struct qib_devdata *dd)
 	 */
 	devid = parent->device;
 	if (devid >= 0x25e2 && devid <= 0x25fa) {
-		u8 rev;
-
 		/* 5000 P/V/X/Z */
-		pci_read_config_byte(parent, PCI_REVISION_ID, &rev);
-		if (rev <= 0xb2)
+		if (parent->revision <= 0xb2)
 			bits = 1U << 10;
 		else
 			bits = 7U << 10;