TraceProcessor: don't skip log events < first clock snapshot

The code was logically broken. The clock snapshot does NOT always
match the beginning of the trace. It matches the very first time
the buffer is read. In ring-buffer-mode that matches the END
of the trace.

Bug: 122243384
Test: tools/diff_test_trace_processor.py
Change-Id: I25ef68f71c2a32fde150e839daeb43bcf3f727d2
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index e4621d2..2906e89 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -20,7 +20,8 @@
     # lines in them.
     long_line_sources = lambda x: input.FilterSourceFile(
             x, white_list=".*",
-            black_list=['Android[.]bp', '.*[.]json$', '.*[.]sql$', '.*[.]out$'])
+            black_list=['Android[.]bp', '.*[.]json$', '.*[.]sql$', '.*[.]out$',
+                        'test/trace_processor/index$'])
     results = []
     results += input.canned_checks.CheckDoNotSubmit(input, output)
     results += input.canned_checks.CheckChangeHasNoTabs(input, output)