broadband-modem-qmi: add a temporary assure_qmi_client() helper

ensure_qmi_client() uses g_simple_async_report_take_gerror_in_idle(),
which can't be mixed with GTask. To allow migrating remaining
MMBroadbandModemQmi code to use GTask in a series of smaller patches,
this patch adds a temporary assure_qmi_client() helper, which mimics
ensure_qmi_client() but uses g_task_report_new_error(). Once all the
MMBroadbandModemQmi code is migrated to use GTask, we will drop the old
ensure_qmi_client() and renames assure_qmi_client() back to
ensure_qmi_client().

src/mm-broadband-modem-qmi.c

@@ -187,6 +187,26 @@ ensure_qmi_client (MMBroadbandModemQmi *self,
     return TRUE;
 }
 
+static gboolean
+assure_qmi_client (MMBroadbandModemQmi *self,
+                   QmiService service,
+                   QmiClient **o_client,
+                   GAsyncReadyCallback callback,
+                   gpointer user_data)
+{
+    GError *error = NULL;
+    QmiClient *client;
+
+    client = peek_qmi_client (self, service, &error);
+    if (!client) {
+        g_task_report_error (self, callback, user_data, assure_qmi_client, error);
+        return FALSE;
+    }
+
+    *o_client = client;
+    return TRUE;
+}
+
 /*****************************************************************************/
 /* Power cycle */