dbus: Fix a couple of warnings

(cherry picked from commit 21e8a014)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/control/dbus/dbus_root.c

@@ -398,7 +398,7 @@ DBUS_METHOD( GetAllProperties )
     OUT_ARGUMENTS;
 
     DBusError error;
-    DBusMessageIter dict, entry, v;
+    DBusMessageIter dict;
 
     char *const psz_interface_name = NULL;