[grilo-plugins] tracker: fix wrong usage of g_assert()

[Xavier Claessens <xclaesse src gnome org>]

commit 6d5fb32ca46bc4a32881772f0c7a1fecf4e27229
Author: Xavier Claessens <xavier claessens collabora com>
Date:   Wed Sep 23 17:06:41 2015 -0400

    tracker: fix wrong usage of g_assert()
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746974

 src/tracker/grl-tracker-source-notif.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)
---
diff --git a/src/tracker/grl-tracker-source-notif.c b/src/tracker/grl-tracker-source-notif.c
index 3e23024..e0871dc 100644
--- a/src/tracker/grl-tracker-source-notif.c
+++ b/src/tracker/grl-tracker-source-notif.c
@@ -375,10 +375,7 @@ tracker_evt_update_items_cb (gpointer              key,
 
   GRL_DEBUG ("%s: evt=%p", __FUNCTION__, evt);
 
-  if (!source) {
-    g_assert ("\tnot in cache ???");
-    return;
-  }
+  g_assert (source != NULL);
 
   if (!grl_tracker_source_can_notify (source)) {
     GRL_DEBUG ("\tno notification for source %s...",