Rename variables to address pep8 error

Without rename, we see this:
    E741 ambiguous variable name 'l'

Change-Id: Ic1d357db594dd6f8f8db162033b6cf408e84453c
Story: 2007515
Task: 39775
(cherry picked from commit 1c1cfd71)

magnumclient/common/cliutils.py

@@ -404,8 +404,8 @@ def get_service_type(f):
     return getattr(f, 'service_type', None)
 
 
-def pretty_choice_list(l):
-    return ', '.join("'%s'" % i for i in l)
+def pretty_choice_list(lst):
+    return ', '.join("'%s'" % i for i in lst)
 
 
 def exit(msg=''):

magnumclient/common/utils.py

@@ -118,12 +118,12 @@ def format_labels(lbls, parse_comma=True):
             lbls = lbls[0].replace(';', ',').split(',')
 
     labels = {}
-    for l in lbls:
+    for lbl in lbls:
         try:
-            (k, v) = l.split(('='), 1)
+            (k, v) = lbl.split(('='), 1)
         except ValueError:
             raise exc.CommandError(_('labels must be a list of KEY=VALUE '
-                                     'not %s') % l)
+                                     'not %s') % lbl)
         if k not in labels:
             labels[k] = v
         else: