Fix pylint warning W0108: Lambda may not be necessary

Remove unnecessary usage of lambda.

Change-Id: I06d41933057d60d15d307ee800cca052a44754c6
diff --git a/git_command.py b/git_command.py
index 39f795f..e5e28f3 100644
--- a/git_command.py
+++ b/git_command.py
@@ -88,7 +88,7 @@
       ver_str = git.version()
       if ver_str.startswith('git version '):
         _git_version = tuple(
-          map(lambda x: int(x),
+          map(int,
             ver_str[len('git version '):].strip().split('-')[0].split('.')[0:3]
           ))
       else:
@@ -110,7 +110,7 @@
   if min_version <= git_version:
     return True
   if fail:
-    need = '.'.join(map(lambda x: str(x), min_version))
+    need = '.'.join(map(str, min_version))
     print >>sys.stderr, 'fatal: git %s or later required' % need
     sys.exit(1)
   return False