selftests: forwarding: move shblock tc support check to a separate helper

The shared block support is only needed for tc_shblock.sh. No need to
require that for other test.

Signed-off-by: Jiri Pirko <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

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

···
 		echo "SKIP: iproute2 too old; tc is missing JSON support"
 		exit 1
 	fi
+}
 
+check_tc_shblock_support()
+{
 	tc filter help 2>&1 | grep block &> /dev/null
 	if [[ $? -ne 0 ]]; then
 		echo "SKIP: iproute2 too old; tc is missing shared block support"

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

···
 	ip link set $swp2 address $swp2origmac
 }
 
+check_tc_shblock_support
+
 trap cleanup EXIT
 
 setup_prepare