_release_lock should be used instead of release_lock.
sigerr is introduced so that it can be redefined by
xen-hotplug-common.sh to a version which writes error status to
xenstore.
Signed-off-by: Kouya Shimura <kouya@jp.fujitsu.com>
xen-unstable changeset: 21738:473c170bca8d
xen-unstable date: Tue Jul 06 13:10:14 2010 +0100