liquidio: Use pcie_flr() instead of reimplementing it

octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
bit, which bypasses timing requirements imposed by the PCIe spec.
This patch fixes the function to use the pcie_flr() interface instead.
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c

@@ -260,9 +260,7 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
 		dev_info(&oct->pci_dev->dev,
 			 "got a request for FLR from VF that owns DPI ring %u\n",
 			 mbox->q_no);
-		pcie_capability_set_word(
-			oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
-			PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
+		pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
 		break;
 
 	case OCTEON_PF_CHANGED_VF_MACADDR: