Fix handling of streams waiting for concurrency

src/core/ext/transport/chttp2/transport/chttp2_transport.c

@@ -1623,6 +1623,7 @@ void grpc_chttp2_mark_stream_closed(grpc_exec_ctx *exec_ctx,
       remove_stream(exec_ctx, t, s->id,
                     removal_error(GRPC_ERROR_REF(error), s, "Stream removed"));
     }
+    grpc_chttp2_list_remove_waiting_for_concurrency(t, s);
     GRPC_CHTTP2_STREAM_UNREF(exec_ctx, s, "chttp2");
   }
   GRPC_ERROR_UNREF(error);

src/core/ext/transport/chttp2/transport/internal.h

@@ -496,6 +496,8 @@ void grpc_chttp2_list_add_waiting_for_concurrency(grpc_chttp2_transport *t,
                                                   grpc_chttp2_stream *s);
 int grpc_chttp2_list_pop_waiting_for_concurrency(grpc_chttp2_transport *t,
                                                  grpc_chttp2_stream **s);
+void grpc_chttp2_list_remove_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                     grpc_chttp2_stream *s);
 
 void grpc_chttp2_list_add_stalled_by_transport(grpc_chttp2_transport *t,
                                                grpc_chttp2_stream *s);

src/core/ext/transport/chttp2/transport/stream_lists.c

@@ -158,6 +158,11 @@ int grpc_chttp2_list_pop_waiting_for_concurrency(grpc_chttp2_transport *t,
   return stream_list_pop(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
 }
 
+void grpc_chttp2_list_remove_waiting_for_concurrency(grpc_chttp2_transport *t,
+                                                     grpc_chttp2_stream *s) {
+  stream_list_maybe_remove(t, s, GRPC_CHTTP2_LIST_WAITING_FOR_CONCURRENCY);
+}
+
 void grpc_chttp2_list_add_stalled_by_transport(grpc_chttp2_transport *t,
                                                grpc_chttp2_stream *s) {
   stream_list_add(t, s, GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT);