Fix implicit-fallthrough warnings in AVDVirglRenderer.cpp etc.

am: d282cb97

Change-Id: I7c6252f82dfb9fefce714fbfb1a0e0ff38670737

host/commands/emugen/main.cpp

@@ -70,7 +70,7 @@ int main(int argc, char *argv[])
             break;
         case ':':
             fprintf(stderr, "Missing argument !!\n");
-            // fall through
+            [[fallthrough]];
         default:
             usage(argv[0]);
             exit(0);

host/libs/virglrenderer/AVDVirglRenderer.cpp

@@ -788,7 +788,7 @@ int virgl_renderer_create_fence(int client_fence_id, uint32_t cmd_type) {
                 g_last_submit_cmd_ctx->setFence(client_fence_id);
                 break;
             }
-            // Fall through
+            [[fallthrough]];
         default: {
             std::lock_guard<std::mutex> lk(g_fence_deque_mutex);
             g_fence_deque.push_back(client_fence_id);