scripts: do not chmod u+w the whole source directory
Doing a chmod on the whole source dir after every packages
are extracted can take a hell of a lot of time.
The offending packages are far from legion, and they now
have their own chmod u+w to cleanup their own mess...
Reported-by: ANDY KENNEDY <ANDY.KENNEDY@adtran.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>