[NaCl SDK] Update getos.py tests to match new behaviour.

The revision reported by getos is now a string rather
than an integer (since we use git shas now).

The behavior was changes in
https://codereview.chromium.org/502883002 but
unfortunately the NaCl SDK bot are still not part
of the CQ so it slipped through.

BUG=406993
R=binji@chromium.org

Review URL: https://codereview.chromium.org/507673003

Cr-Commit-Position: refs/heads/master@{#291926}

native_client_sdk/src/tools/tests/getos_test.py

@@ -117,7 +117,7 @@ class TestGetosWithTempdir(TestCaseExtended):
 
   def testGetSDKVersion(self):
     """correctly parses README to find SDK version."""
-    expected_version = (16, 196)
+    expected_version = (16, '196')
     with open(os.path.join(self.tempdir, 'README'), 'w') as out:
       out.write('Version: %s\n' % expected_version[0])
       out.write('Chrome Revision: %s\n' % expected_version[1])