mmc: use correct unregister function for led trigger

We register a simple trigger so make sure we use the corresponding
unregister function.

(Also means we get a dummy function when triggers aren't compiled in)
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

drivers/mmc/core/host.c

@@ -143,7 +143,7 @@ void mmc_remove_host(struct mmc_host *host)
 
 	device_del(&host->class_dev);
 
-	led_trigger_unregister(host->led);
+	led_trigger_unregister_simple(host->led);
 
 	spin_lock(&mmc_host_lock);
 	idr_remove(&mmc_host_idr, host->index);