xenserver: Print program name on error in dump-vif-details

diff --git a/xenserver/root_vswitch_scripts_dump-vif-details b/xenserver/root_vswitch_scripts_dump-vif-details
index b0ceb40..387c31b 100755 (executable)
--- a/xenserver/root_vswitch_scripts_dump-vif-details
+++ b/xenserver/root_vswitch_scripts_dump-vif-details
@@ -62,7 +62,7 @@ def dump_vif_info(domid, devid, vif_ref):
        
 if __name__ == '__main__':
        if (len(sys.argv) != 3):
-               sys.stderr.write("ERROR: %s <domid> <devid>\n")
+               sys.stderr.write("ERROR: %s <domid> <devid>\n" % sys.argv[0])
                sys.exit(1)
 
        domid = sys.argv[1]