Remove all extern C
diff --git a/src/core/ext/filters/deadline/deadline_filter.cc b/src/core/ext/filters/deadline/deadline_filter.cc
index 849ce71..5db7584 100644
--- a/src/core/ext/filters/deadline/deadline_filter.cc
+++ b/src/core/ext/filters/deadline/deadline_filter.cc
@@ -382,7 +382,7 @@
              : true;
 }
 
-extern "C" void grpc_deadline_filter_init(void) {
+void grpc_deadline_filter_init(void) {
   grpc_channel_init_register_stage(
       GRPC_CLIENT_DIRECT_CHANNEL, GRPC_CHANNEL_INIT_BUILTIN_PRIORITY,
       maybe_add_deadline_filter, (void*)&grpc_client_deadline_filter);
@@ -391,4 +391,4 @@
       maybe_add_deadline_filter, (void*)&grpc_server_deadline_filter);
 }
 
-extern "C" void grpc_deadline_filter_shutdown(void) {}
+void grpc_deadline_filter_shutdown(void) {}