[S390] cio: introduce consistent subchannel scanning

Previously, there were multiple subchannel scanning mechanisms
which could potentially conflict with each other. Fix this problem
by moving blacklist and ccw driver triggered scanning to the
existing evaluation method.

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/idset.h b/drivers/s390/cio/idset.h
index ca1398a..7543da4 100644
--- a/drivers/s390/cio/idset.h
+++ b/drivers/s390/cio/idset.h
@@ -22,5 +22,6 @@
 int idset_sch_contains(struct idset *set, struct subchannel_id id);
 int idset_sch_get_first(struct idset *set, struct subchannel_id *id);
 int idset_is_empty(struct idset *set);
+void idset_add_set(struct idset *to, struct idset *from);
 
 #endif /* S390_IDSET_H */