selftests: forwarding: add check_driver() helper

Add a helper to be used to check if the netdevice is backed by specified
driver.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Benjamin Poirier <bpoirier@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/net/forwarding/lib.sh

@@ -283,6 +283,18 @@ if [[ "$(id -u)" -ne 0 ]]; then
 	exit $ksft_skip
 fi
 
+check_driver()
+{
+	local dev=$1; shift
+	local expected=$1; shift
+	local driver_name=`driver_name_get $dev`
+
+	if [[ $driver_name != $expected ]]; then
+		echo "SKIP: expected driver $expected for $dev, got $driver_name instead"
+		exit $ksft_skip
+	fi
+}
+
 if [[ "$CHECK_TC" = "yes" ]]; then
 	check_tc_version
 fi