[S390] cio: idset use actual number of ssids

The functions idset_sch_new and for_each_subchannel_staged
use different values for the number of subchannel sets. Make
it consistent by changing idset_sch_new to also use the actual
number of subchannel sets.

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.h b/drivers/s390/cio/css.h
index 54acdaa..68d6b0b 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -111,6 +111,7 @@
 extern int css_probe_device(struct subchannel_id);
 extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
 extern int css_init_done;
+extern int max_ssid;
 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
 			       int (*fn_unknown)(struct subchannel_id,
 			       void *), void *data);