xend: Fix removing /vm/UUID/device paths when device cannot be disconnected

This is a corrected version of a patch commited as c/s 19250 and
reverted by c/s 19314. Thanks to "trap sigerr ERR" in
xen-hotplug-common.sh the xen-hotplug-cleanup would exit when reading
/local/domain/ID/vm fails thus skipping all the xenstore-rm lines in
the rest of the script.

Change deviceDestroy behavior to remove /vm/UUID/device/...
path only when force was used (as it already does so for both frontend
and backend) and do the removing from xen-hotplug-cleanup script when
we are sure the device is really not attached to the guest any more.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

tools/python/xen/xend/server/DevController.py

@@ -235,8 +235,8 @@ class DevController:
                 xstransact.Remove(backpath)
             xstransact.Remove(frontpath)
 
-        # xstransact.Remove(self.devicePath()) ?? Below is the same ?
-        self.vm._removeVm("device/%s/%d" % (self.deviceClass, dev))
+            # xstransact.Remove(self.devicePath()) ?? Below is the same ?
+            self.vm._removeVm("device/%s/%d" % (self.deviceClass, dev))
 
     def configurations(self, transaction = None):
         return map(lambda x: self.configuration(x, transaction), self.deviceIDs(transaction))