Fixed issues that occured with pylint 1.7.2

When updating the previously used version of pylint 1.6.5 to 1.7.2
some new issues where found.

This patch fixes these issues:

************* Module kas.config
E:402, 0: Bad option value 'redefined-variable-type' (bad-option-value)
************* Module kas.includehandler
E: 33, 0: No name 'version' in module 'distutils' (no-name-in-module)
E: 33, 0: Unable to import 'distutils.version' (import-error)
R:239,12: Unnecessary "else" after "return" (no-else-return)
************* Module kas.libkas
C:214, 7: Do not use `len(SEQUENCE)` as condition value
(len-as-condition)
************* Module kas.repos
R: 54,12: Unnecessary "else" after "return" (no-else-return)

Signed-off-by: Claudius Heine <ch@denx.de>

kas/libkas.py

@@ -220,7 +220,7 @@ def repo_checkout(config, repo):
     (_, output) = run_cmd(['/usr/bin/git', 'diff', '--shortstat'],
                           env=config.environ, cwd=repo.path,
                           fail=False)
-    if len(output):
+    if output:
         logging.warning('Repo %s is dirty. no checkout', repo.name)
         return