bisect-kit: revise output messages for non-noisy case

Classic (non-noisy) bisection is special case of noisy bisection.
Although the more general messages apply to non-noisy case, they make
users confused. This CL improves output messages for non-noisy case.

BUG=chromium:776314
TEST=None

Change-Id: I34f1d8e54c5f37b5464dbbc9f1cfb9dc448c8662
Reviewed-on: https://chromium-review.googlesource.com/867802
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Kuang-che Wu <kcwu@chromium.org>
Reviewed-by: Owen Lin <owenlin@chromium.org>
diff --git a/bisect_kit/cli.py b/bisect_kit/cli.py
index d39ab89..fa21ac3 100644
--- a/bisect_kit/cli.py
+++ b/bisect_kit/cli.py
@@ -343,6 +343,7 @@
     See init command's help message for more detail.
     """
     config, revlist = self.domain_cls.init(opts)
+    logger.info('found %d revs to bisect', len(revlist))
     logger.debug('revlist %r', revlist)
     if 'new' not in config:
       config['new'] = opts.new