Turn implicit fallthrow warnings into errors

Test: m netd ndc bpfloader libnetd_client netd_integration_test netd_unit_test netd_benchmark
Change-Id: Ie607ab784fd6470d7dc7654b07f33f7f5b943118
diff --git a/resolv/res_query.cpp b/resolv/res_query.cpp
index 526586a..dd6b1fb 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]];
+                    break;
                 case HOST_NOT_FOUND:
                     /* keep trying */
                     break;