buildman: Add verbose option to display errors as they happen

Normally buildman operates in two passes - one to do the build and another
to summarise the errors. Add a verbose option (-v) to display build problems
as they happen. With -e also given, this will display errors too.

When building the current source tree (rather than a list of commits in a
branch), both -v and -e are enabled automatically.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index d8fa74b..cc8593f 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -158,6 +158,8 @@
                 series)
     else:
         series = None
+        options.verbose = True
+        options.show_errors = True
 
     # By default we have one thread per CPU. But if there are not enough jobs
     # we can have fewer threads and use a high '-j' value for make.
@@ -216,4 +218,4 @@
             builder.ShowSummary(commits, board_selected)
         else:
             builder.BuildBoards(commits, board_selected,
-                                options.keep_outputs)
+                                options.keep_outputs, options.verbose)