Fix -Wimplicit-fallthrough warnings in netd

Test: atest netd_integration_test
Change-Id: Ib5ab9661fb429fdccd6a4c4b5893831ff5fe104e
diff --git a/resolv/getaddrinfo.cpp b/resolv/getaddrinfo.cpp
index 8abfea8..123f609 100644
--- a/resolv/getaddrinfo.cpp
+++ b/resolv/getaddrinfo.cpp
@@ -1874,7 +1874,7 @@
             switch (h_errno) {
                 case NO_DATA:
                     got_nodata++;
-                    /* FALLTHROUGH */
+                    [[fallthrough]];
                 case HOST_NOT_FOUND:
                     /* keep trying */
                     break;
@@ -1884,7 +1884,7 @@
                         got_servfail++;
                         break;
                     }
-                    /* FALLTHROUGH */
+                    [[fallthrough]];
                 default:
                     /* anything else implies that we're done */
                     done++;