Python3.x undefined name 'xrange'

Changes:
     - In Python 3, xrange() was removed,
       and the built-in range() function i
       was modified to behave like Pythoni
       2.xx xrange(), returning an iterator.

Tested:
     - NA
Change-Id: I9c4e9b628e445bc019a8d35c1a253b7cca83c449
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/lib/pythonutil.py b/lib/pythonutil.py
index bf5e1a4..cba8654 100644
--- a/lib/pythonutil.py
+++ b/lib/pythonutil.py
@@ -4,7 +4,7 @@
 
 def calcDottedNetmask(mask):
     bits = 0
-    for i in xrange(32 - mask, 32):
+    for i in range(32 - mask, 32):
         bits |= 1 << i
     packed_value = pack("!I", bits)
     addr = inet_ntoa(packed_value)