scripts: fix tools override

The tools found by the new autostuff configure can contain arguments,
for example: grep -E

This needs separating the paths set for the Makfile from the paths
set for the scripts.

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

reporter_name="Thomas Petazzoni"

reporter_url="http://www.free-electrons.com/"

reporter_comment="Very basic testing only"