ionic: use pci_is_enabled not open code

Since there is a utility available for this, use
the API rather than open code.

Fixes: 13943d6 ("ionic: prevent pci disable of already disabled device")
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -223,7 +223,7 @@ static void ionic_clear_pci(struct ionic *ionic)
 	ionic_unmap_bars(ionic);
 	pci_release_regions(ionic->pdev);
 
-	if (atomic_read(&ionic->pdev->enable_cnt) > 0)
+	if (pci_is_enabled(ionic->pdev))
 		pci_disable_device(ionic->pdev);
 }