net: marvell: fix a missing check of acpi_match_device

When acpi_match_device fails, its return value is NULL. Directly using
the return value without a check may result in a NULL-pointer
dereference. The fix checks if acpi_match_device fails, and if so,
returns -EINVAL.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -5255,6 +5255,8 @@ static int mvpp2_probe(struct platform_device *pdev)
 	if (has_acpi_companion(&pdev->dev)) {
 		acpi_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
 					    &pdev->dev);
+		if (!acpi_id)
+			return -EINVAL;
 		priv->hw_version = (unsigned long)acpi_id->driver_data;
 	} else {
 		priv->hw_version =