ionic: prevent pci disable of already disabled device

If a reset fails, the PCI device is left in a disabled
state, so don't try to disable it again on driver remove.
This prevents a scary looking WARN trace in the kernel log.

    ionic 0000:2b:00.0: disabling already-disabled device
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_bus_pci.c

@@ -217,7 +217,9 @@ static void ionic_clear_pci(struct ionic *ionic)
 {
 	ionic_unmap_bars(ionic);
 	pci_release_regions(ionic->pdev);
-	pci_disable_device(ionic->pdev);
+
+	if (atomic_read(&ionic->pdev->enable_cnt) > 0)
+		pci_disable_device(ionic->pdev);
 }
 
 static int ionic_setup_one(struct ionic *ionic)