[autotest] Remove identical default parameter

BUG=chromium:672348
TEST=None

Change-Id: Ic12b1f4ca5fed29c0a043e168d410841334c817e
Reviewed-on: https://chromium-review.googlesource.com/452695
Commit-Ready: Allen Li <ayatane@chromium.org>
Tested-by: Allen Li <ayatane@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/server/cros/dynamic_suite/suite.py b/server/cros/dynamic_suite/suite.py
index 5504b64..82fa9d0 100644
--- a/server/cros/dynamic_suite/suite.py
+++ b/server/cros/dynamic_suite/suite.py
@@ -892,9 +892,7 @@
             match ratio.
     """
     logging.debug('Getting control file list for suite: %s', suite_name)
-    retriever = _get_cf_retriever(cf_getter,
-                                  forgiving_parser=True)
-    tests = retriever.retrieve_for_suite(suite_name)
+    tests = _get_cf_retriever(cf_getter).retrieve_for_suite(suite_name)
     logging.debug('Parsed %s control files.', len(tests))
     similarities = {}
     for test in tests.itervalues():