[S390] cio: dont kfree vmalloced memory

Don't use kfree to free memory allocated by vmalloc.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index f018835..b43f769 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -971,7 +971,7 @@
 out:
 	crw_unregister_handler(CRW_RSC_CSS);
 	chsc_free_sei_area();
-	kfree(slow_subchannel_set);
+	idset_free(slow_subchannel_set);
 	pr_alert("The CSS device driver initialization failed with "
 		 "errno=%d\n", ret);
 	return ret;
@@ -993,7 +993,7 @@
 	bus_unregister(&css_bus_type);
 	crw_unregister_handler(CRW_RSC_CSS);
 	chsc_free_sei_area();
-	kfree(slow_subchannel_set);
+	idset_free(slow_subchannel_set);
 	isc_unregister(IO_SCH_ISC);
 }