fix a few errors revealed by pylint

cli/koji

@@ -31,7 +31,6 @@ try:
     import ast
 except ImportError:
     ast = None
-    pass
 import ConfigParser
 import base64
 import errno
@@ -5202,7 +5201,7 @@ def _build_image_indirection(options, task_opts, session, args):
 
     tmp_target = session.getBuildTarget(task_opts.target)
     if not tmp_target:
-        raise koji.GenericError, _("Unknown build target: %s" % target)
+        raise koji.GenericError, _("Unknown build target: %s" % tmp_target)
     dest_tag = session.getTag(tmp_target['dest_tag'])
     if not dest_tag:
         raise koji.GenericError, _("Unknown destination tag: %s" %

koji/util.py

@@ -142,8 +142,10 @@ def dslice_ex(dict, keys, strict=True):
             del ret[key]
     return ret
 
-def call_with_argcheck(func, args, kwargs={}):
+def call_with_argcheck(func, args, kwargs=None):
     """Call function, raising ParameterError if args do not match"""
+    if kwargs is None:
+        kwargs = {}
     try:
         return func(*args, **kwargs)
     except TypeError, e: