ixgbe: Fix device ref count bug

The device lookup neglected to do a pci_dev_put() to decrement the
device reference count.

Reported-by: Elena Gurevich <elena.gurevich@toganetworks.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -7758,6 +7758,8 @@ static pci_ers_result_t ixgbe_io_error_detected(struct pci_dev *pdev,
 		if (vfdev) {
 			e_dev_err("Issuing VFLR to VF %d\n", vf);
 			pci_write_config_dword(vfdev, 0xA8, 0x00008000);
+			/* Free device reference count */
+			pci_dev_put(vfdev);
 		}
 
 		pci_cleanup_aer_uncorrect_error_status(pdev);