bnxt_en: close & open NIC, only when the interface is in running state.

bnxt_restore_pf_fw_resources routine frees PF resources by calling
close_nic and allocates the resources back, by doing open_nic. However,
this is not needed, if the PF is already in closed state.

This bug causes the driver to call open the device and call request_irq()
when it is not needed.  Ultimately, pci_disable_msix() will crash
when bnxt_en is unloaded.

This patch fixes the problem by skipping __bnxt_close_nic and
__bnxt_open_nic inside bnxt_restore_pf_fw_resources routine, if the
interface is not running.

Fixes: 80fcaf4 ("bnxt_en: Restore MSIX after disabling SRIOV.")
Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -8432,13 +8432,20 @@ int bnxt_restore_pf_fw_resources(struct bnxt *bp)
 		return 0;
 
 	bnxt_hwrm_func_qcaps(bp);
-	__bnxt_close_nic(bp, true, false);
+
+	if (netif_running(bp->dev))
+		__bnxt_close_nic(bp, true, false);
+
 	bnxt_clear_int_mode(bp);
 	rc = bnxt_init_int_mode(bp);
-	if (rc)
-		dev_close(bp->dev);
-	else
-		rc = bnxt_open_nic(bp, true, false);
+
+	if (netif_running(bp->dev)) {
+		if (rc)
+			dev_close(bp->dev);
+		else
+			rc = bnxt_open_nic(bp, true, false);
+	}
+
 	return rc;
 }