staging: vchiq: call unregister_chrdev_region() when driver registration fails

This undoes the previous call to alloc_chrdev_region() on failure,
and is probably what was meant originally given the label name.
Signed-off-by: Marcelo Diop-Gonzalez <marcgonzalez@google.com>
Cc: stable <stable@vger.kernel.org>
Fixes: 187ac53e ("staging: vchiq_arm: rework probe and init functions")
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20191203153921.70540-1-marcgonzalez@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -3309,7 +3309,7 @@ static int __init vchiq_driver_init(void)
 	return 0;
 
 region_unregister:
-	platform_driver_unregister(&vchiq_driver);
+	unregister_chrdev_region(vchiq_devid, 1);
 
 class_destroy:
 	class_destroy(vchiq_class);