Fix more pylint warnings.

* add .pylintrc to use 2 space indentation
* rename single-letter local variables

Test: ./warn.py build.log > warnings.html
Change-Id: I2ca56a6cb130a9d6c73328c5592ad7cde8a974ab
diff --git a/tools/warn/.pylintrc b/tools/warn/.pylintrc
new file mode 100644
index 0000000..6aeaed6
--- /dev/null
+++ b/tools/warn/.pylintrc
@@ -0,0 +1,4 @@
+[FORMAT]
+
+# Two spaces for each indentation level.
+indent-string='  '