bins.pl script: don't hide errors, they might be useful

Don't use make -j as it uses an unlimited number of jobs and can
severely slow down machines and/or make the build fail if processes
can't be created

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26533 a1c6a512-1295-4272-9138-f99709370657
1 file changed