get_maintainer.pl quotes names which it considers unsafe, i.e. anything
containing [^a-zA-Z0-9_ \-]. This confuses patman, it will duplicate
addresses which are also in Series-to/cc. Strip the quotes.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Simon Glass <sjg@chromium.org>