[tools/perf] Remove a redundant argument from trace processor call

This will allow running TBMv3 metrics on Windows.

Bug: 990304
Change-Id: Id53fe61c931b36b386e6feea461447657ca24f58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2005008
Commit-Queue: Mikhail Khokhlov <khokhlov@google.com>
Reviewed-by: Deepanjan Roy <dproy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732865}

tools/perf/core/tbmv3/trace_processor.py

@@ -101,7 +101,6 @@ def RunMetric(trace_processor_path, trace_file, metric_name):
       trace_processor_path,
       '--run-metrics', metric_files.sql,
       '--metrics-output', 'json',
-      '--extra-metrics', METRICS_PATH,
       trace_file,
   )
   measurements = json.loads(output)