tools: remove /var/lock/subsys from install target

tools: remove /var/lock/subsys from install target

/var/lock/subsys is used only in tools/hotplug/Linux/init.d/xendomains.
The start() function already does a "mkdir /var/lock/subsys", so its not
required to create this directory during make install|rpmball.

Without this change installing the resulting xen.rpm will fail on
systems where /var/lock is a symlink. rpm complains that '/var/lock'
(the symlink) is already owned by some other system rpm package.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>