Fix -Wimplicit-fallthrough warnings in netd

Test: atest netd_integration_test
Change-Id: Ib5ab9661fb429fdccd6a4c4b5893831ff5fe104e
diff --git a/resolv/res_query.cpp b/resolv/res_query.cpp
index c0fe8b9..526586a 100644
--- a/resolv/res_query.cpp
+++ b/resolv/res_query.cpp
@@ -273,7 +273,7 @@
             switch (statp->res_h_errno) {
                 case NO_DATA:
                     got_nodata++;
-                    /* FALLTHROUGH */
+                    [[fallthrough]];
                 case HOST_NOT_FOUND:
                     /* keep trying */
                     break;
@@ -283,7 +283,7 @@
                         got_servfail++;
                         break;
                     }
-                    /* FALLTHROUGH */
+                    [[fallthrough]];
                 default:
                     /* anything else implies that we're done */
                     done++;