xm: domid casting bug

- This patch fixes a small casting bug in xm.  The value of domid was
  not returned as an int, causing commands like 'xm vncviewer domid'
  to fail.

Signed-off-by: George Coker <gscoker@alpha.ncsc.mil>

tools/python/xen/xm/main.py

@@ -1812,7 +1812,7 @@ def domain_name_to_domid(domain_name):
     else:
         dom = server.xend.domain(domain_name)
         domid = int(sxp.child_value(dom, 'domid', '-1'))
-    return domid
+    return int(domid)
 
 def xm_vncviewer(args):
     autopass = False;