selftests/net: l2_tos_ttl_inherit.sh: Set IPv6 addresses with "nodad".

The ping command can run before DAD completes. In that case, ping may
fail and break the selftest.

We don't need DAD here since we're working on isolated device pairs.

Fixes: b690842d ("selftests/net: test l2 tunnel TOS/TTL inheriting")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/net/l2_tos_ttl_inherit.sh

@@ -137,8 +137,8 @@ setup() {
 		if [ "$type" = "gre" ]; then
 			type="ip6gretap"
 		fi
-		ip addr add fdd1:ced0:5d88:3fce::1/64 dev veth0
-		$ns ip addr add fdd1:ced0:5d88:3fce::2/64 dev veth1
+		ip addr add fdd1:ced0:5d88:3fce::1/64 dev veth0 nodad
+		$ns ip addr add fdd1:ced0:5d88:3fce::2/64 dev veth1 nodad
 		ip link add name tep0 type $type $local_addr1 \
 		remote fdd1:ced0:5d88:3fce::2 tos $test_tos ttl $test_ttl \
 		$vxlan $geneve
@@ -170,8 +170,8 @@ setup() {
 		ip addr add 198.19.0.1/24 brd + dev ${parent}0
 		$ns ip addr add 198.19.0.2/24 brd + dev ${parent}1
 	elif [ "$inner" = "6" ]; then
-		ip addr add fdd4:96cf:4eae:443b::1/64 dev ${parent}0
-		$ns ip addr add fdd4:96cf:4eae:443b::2/64 dev ${parent}1
+		ip addr add fdd4:96cf:4eae:443b::1/64 dev ${parent}0 nodad
+		$ns ip addr add fdd4:96cf:4eae:443b::2/64 dev ${parent}1 nodad
 	fi
 }