[tools/perf] Fix run_benchmark list command

Bug: 996493
Change-Id: I3ebbe717f4ac64fede6c64afcab142918a9edaf9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1763762Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Juan Antonio Navarro Pérez <perezju@chromium.org>
Cr-Commit-Position: refs/heads/master@{#689865}

tools/perf/core/results_processor/processor.py

@@ -82,7 +82,7 @@ def ProcessOptions(options):
   Args:
     options: An options object with values parsed from the command line.
   """
-  if not hasattr(options, 'output_formats'):
+  if not getattr(options, 'output_formats', None):
     return
 
   options.output_dir = os.path.expanduser(options.output_dir)