net: ena: fix warning in rmmod caused by double iounmap

BugLink: http://bugs.launchpad.net/bugs/1798182

Memory mapped with devm_ioremap is automatically freed when the driver
is disconnected from the device. Therefore there is no need to
explicitly call devm_iounmap.

Fixes: 0857d92f ("net: ena: add missing unmap bars on device removal")
Fixes: 411838e7 ("net: ena: fix rare kernel crash when bar memory remap fails")
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit d79c3888)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khalid Elmously <khalid.elmously@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -3084,15 +3084,8 @@ static int ena_rss_init_default(struct ena_adapter *adapter)
 
 static void ena_release_bars(struct ena_com_dev *ena_dev, struct pci_dev *pdev)
 {
-	int release_bars;
+	int release_bars = pci_select_bars(pdev, IORESOURCE_MEM) & ENA_BAR_MASK;
 
-	if (ena_dev->mem_bar)
-		devm_iounmap(&pdev->dev, ena_dev->mem_bar);
-
-	if (ena_dev->reg_bar)
-		devm_iounmap(&pdev->dev, ena_dev->reg_bar);
-
-	release_bars = pci_select_bars(pdev, IORESOURCE_MEM) & ENA_BAR_MASK;
 	pci_release_selected_regions(pdev, release_bars);
 }