[BLKTAP] Fix in xend to properly destroy blktap devices when deviceClass=='tap'

Submitted by Andres Lagar Cavilla

tools/python/xen/xend/XendDomainInfo.py

@@ -1087,6 +1087,15 @@ class XendDomainInfo:
     ## public:
 
     def destroyDevice(self, deviceClass, devid):
+	if type(devid) is str:
+	    devicePath = '%s/device/%s' % (self.dompath, deviceClass)
+	    for entry in xstransact.List(devicePath):
+		backend = xstransact.Read('%s/%s' % (devicePath, entry), "backend")
+		devName = xstransact.Read(backend, "dev")
+		if devName == devid:
+		    # We found the integer matching our devid, use it instead
+		    devid = entry
+        	    break
         return self.getDeviceController(deviceClass).destroyDevice(devid)