Cleans up some minor issues in cpplint

Summary:
- Corrected typo in install instructions
- Sets the default binary to cpplint.py

Test Plan:
- Running the unit tests.

You may need to check your test environment is set up with the latest
cpplint.py available, since the default binary is being changed.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin

Maniphest Tasks: T10157

Differential Revision: https://secure.phabricator.com/D15030

src/lint/linter/ArcanistCpplintLinter.php

@@ -14,12 +14,12 @@ final class ArcanistCpplintLinter extends ArcanistExternalLinter {
   }
 
   public function getDefaultBinary() {
-    return 'cpplint';
+    return 'cpplint.py';
   }
 
   public function getInstallInstructions() {
     return pht(
-      'Install cpplint.py using `%s`, and place it in your path with the'.
+      'Install cpplint.py using `%s`, and place it in your path with the '.
       'appropriate permissions set.',
       'wget https://raw.github.com'.
       '/google/styleguide/gh-pages/cpplint/cpplint.py');