Properly format messages coming out of emitPlaybookBanner

In I7e34206d7968bf128e140468b9a222ecbce3a8f1 we modified how
messages are printed for the playbook banner (and now, footer).

The message wasn't formatted properly due to the lack of assignment.
Additionally, we need to add a line break after these messages,
otherwise the next message starts on the same line.

Change-Id: I808d8908815ffa5fae409e600308dfb9ff9c6e77
1 file changed