Fix compile

src/core/ext/filters/client_channel/client_channel.cc

@@ -402,7 +402,6 @@ static void on_resolver_result_changed_locked(void* arg, grpc_error* error) {
   if (chand->resolver_result != nullptr) {
     if (chand->resolver != nullptr) {
       // Find LB policy name.
-      const char* lb_policy_name = nullptr;
       const grpc_arg* channel_arg = grpc_channel_args_find(
           chand->resolver_result, GRPC_ARG_LB_POLICY_NAME);
       const char* lb_policy_name = grpc_channel_arg_get_string(channel_arg);

test/core/end2end/fixtures/http_proxy_fixture.cc

@@ -413,7 +413,7 @@ static void on_read_request_done(void* arg, grpc_error* error) {
   // If proxy auth is being used, check if the header is present and as expected
   const grpc_arg* proxy_auth_arg = grpc_channel_args_find(
       conn->proxy->channel_args, GRPC_ARG_HTTP_PROXY_AUTH_CREDS);
-  const char* proxy_auth_str = grpc_channel_arg_get_string(proxy_auth_arg);
+  char* proxy_auth_str = grpc_channel_arg_get_string(proxy_auth_arg);
   if (proxy_auth_str != nullptr) {
     bool client_authenticated = false;
     for (size_t i = 0; i < conn->http_request.hdr_count; i++) {