[autotest] Fix bug in report repair stats collection

stats.Counter('%s.SUCCEEDED.%s' % (repair_func.__name__, board)).increment()
This line failed to report stats, because there already exists a counter named
'%s.SUCCEEDED' % repair_func.__name__

Graphite does not allow name collistion on folder and counter.

BUG=chromium:343288
TEST=local repair, confirm Graphite counter exists in chromeos-stats.

Change-Id: I0c4cabff57becb595c08b3cd14481783186826e4
Reviewed-on: https://chromium-review.googlesource.com/186200
Tested-by: Dan Shi <dshi@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
Commit-Queue: Dan Shi <dshi@chromium.org>
1 file changed