Fix for 'no-return-in-nonvoid function intf.c'

MAke sure we always return defined values.
I: Program returns random data in a function
E: vlc-beta no-return-in-nonvoid-function intf.c:341
Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

modules/access/vcdx/intf.c

@@ -338,6 +338,8 @@ static int InitThread( intf_thread_t * p_intf )
     p_intf->p_sys->b_key_pressed = false;
 
     vlc_mutex_unlock( &p_intf->change_lock );
+    /* make sure we return a value */
+    return 0;
 }
 
 /*****************************************************************************