Don't complain that the DNSSL RA option is "unknown".

This option isn't unknown, we just don't support it.

Bug: 69778511
Test: walleye builds, boots, connects to IPv6 network
Change-Id: If3a37d855f404da708fec4a7ba242ed41a493895

libsysutils/src/NetlinkEvent.cpp

@@ -501,6 +501,8 @@ bool NetlinkEvent::parseNdUserOptMessage(const struct nlmsghdr *nh) {
         asprintf(&mParams[0], "INTERFACE=%s", ifname);
         asprintf(&mParams[1], "LIFETIME=%u", lifetime);
         mParams[2] = buf;
+    } else if (opthdr->nd_opt_type == ND_OPT_DNSSL) {
+        // TODO: support DNSSL.
     } else {
         SLOGD("Unknown ND option type %d\n", opthdr->nd_opt_type);
         return false;