sim: avoid passing source of the async object in finish

src/mm-broadband-modem.c

@@ -246,14 +246,14 @@ modem_create_sim_finish (MMIfaceModem *self,
 }
 
 static void
-modem_create_sim_ready (GAsyncInitable *initable,
+modem_create_sim_ready (GObject *source,
                         GAsyncResult *res,
                         GSimpleAsyncResult *simple)
 {
     MMSim *sim;
     GError *error = NULL;
 
-    sim = mm_sim_new_finish (initable, res, &error);
+    sim = mm_sim_new_finish (res, &error);
     if (!sim)
         g_simple_async_result_take_error (simple, error);
     else {

src/mm-sim.c

@@ -1139,13 +1139,16 @@ init_async_context_free (InitAsyncContext *ctx,
 }
 
 MMSim *
-mm_sim_new_finish (GAsyncInitable *initable,
-                   GAsyncResult  *res,
+mm_sim_new_finish (GAsyncResult  *res,
                    GError       **error)
 {
+    GObject *source;
     GObject *sim;
 
-    sim = g_async_initable_new_finish (initable, res, error);
+    source = g_async_result_get_source_object (res);
+    sim = g_async_initable_new_finish (G_ASYNC_INITABLE (source), res, error);
+    g_object_unref (source);
+
     if (!sim)
         return NULL;
 

src/mm-sim.h

@@ -125,8 +125,7 @@ void   mm_sim_new        (MMBaseModem *modem,
                           GCancellable *cancellable,
                           GAsyncReadyCallback callback,
                           gpointer user_data);
-MMSim *mm_sim_new_finish (GAsyncInitable *initable,
-                          GAsyncResult  *res,
+MMSim *mm_sim_new_finish (GAsyncResult  *res,
                           GError       **error);
 
 void     mm_sim_initialize        (MMSim *self,