scripts: do not allow commas in directories, it breaks things

The comma is used by the autotools as separator in many sed expressions,
which break if a directory contains commas.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 reporter_name="Gustavo Zacarias <gustavo@zacarias.com.ar>"

 reporter_url="http://sourceware.org/ml/crossgcc/2011-03/msg00028.html"

 reporter_comment=""