search: Fix memory leak

The container returned by g_variant_get_strv() should be
freed with g_free().

https://bugzilla.gnome.org/show_bug.cgi?id=783885

panels/search/cc-search-locations-dialog.c

@@ -374,6 +374,8 @@ switch_tracker_get_mapping (GValue *value,
         break;
     }
 
+  g_free (locations);
+
   g_value_set_boolean (value, found);
   return TRUE;
 }