Staging: echo: fix up remaining checkpatch.pl issues

It's all just minor comment spacing issues.  This patch fixes
up the remaining ones and now the code is checkpatch.pl clean.

Cc: Steve Underwood <steveu@coppice.org>
Cc: David Rowe <david@rowetel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>