buildman: Show a summary of the build result

When buildman finishes it leaves the last summary line visible, which
shows the number of successful builds, builds with warnings and builds
with errors.

It is useful also to see how many builds were done in total along with
the time taken. Show these on a separate line before buildman finishes.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/test.py b/tools/buildman/test.py
index a495df0..fb861e1 100644
--- a/tools/buildman/test.py
+++ b/tools/buildman/test.py
@@ -205,9 +205,9 @@
             if line.text.strip():
                 count += 1
 
-        # We should get two starting messages, then an update for every commit
-        # built.
-        self.assertEqual(count, len(commits) * len(boards) + 2)
+        # We should get two starting messages, an update for every commit built
+        # and a summary message
+        self.assertEqual(count, len(commits) * len(boards) + 3)
         build.SetDisplayOptions(**kwdisplay_args);
         build.ShowSummary(self.commits, board_selected)
         if echo_lines: