Fixing flake8 warnings and errors

flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics --exclude benchmark

Excluding the benchmark directory (due to protobuf generated files)
Also removing some Python2 specific code

buildutils/misc.py

@@ -4,7 +4,6 @@
 # Distributed under the terms of the Modified BSD License.
 
 import os
-import sys
 import logging
 from distutils import ccompiler
 from distutils.sysconfig import customize_compiler
@@ -14,13 +13,8 @@ from subprocess import Popen, PIPE
 pjoin = os.path.join
 
 
-if sys.version_info[0] >= 3:
-    u = lambda x: x
-else:
-    u = lambda x: x.decode('utf8', 'replace')
-
-
 def customize_mingw(cc):
+    """customize mingw"""
     # strip -mno-cygwin from mingw32 (Python Issue #12641)
     for cmd in [cc.compiler, cc.compiler_cxx, cc.compiler_so, cc.linker_exe, cc.linker_so]:
         if '-mno-cygwin' in cmd:
@@ -55,11 +49,10 @@ def get_output_error(cmd):
     try:
         result = Popen(cmd, stdout=PIPE, stderr=PIPE)
     except IOError as e:
-        return -1, u(''), u('Failed to run %r: %r' % (cmd, e))
+        return -1, '', 'Failed to run %r: %r' % (cmd, e)
     so, se = result.communicate()
     # unicode:
     so = so.decode('utf8', 'replace')
     se = se.decode('utf8', 'replace')
 
     return result.returncode, so, se
-