[test] Fix typo in numfuzzer

NOTRY=true
TBR=sergiyb@chromium.org

Bug: chromium:830557
Change-Id: I61510297e5195eb74425c71e41c4d95f080a280d
Reviewed-on: https://chromium-review.googlesource.com/1016420Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52659}

tools/testrunner/num_fuzzer.py

@@ -103,7 +103,7 @@ class NumFuzzer(base_runner.BaseTestRunner):
 
     if options.variants != 'default':
       print ('Only default testing variant is supported with numfuzz')
-        raise base_runner.TestRunnerError()
+      raise base_runner.TestRunnerError()
 
     return True