abort on errors in subdir builds

The current recursive loops do not check the exit status of make
in subdirs which leads to `make` passing even when a subdir failed
to compile or install.

URL: https://bugs.gentoo.org/334727
Signed-off-by: Martin von Gagern <Martin.vGagern@gmx.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>