[S390] memory hotplug: only unassign assigned increments

Make sure that only assigned storage increments are unassigned when
attaching a storage element.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed