build: exit if not running from lbmk directory

there's no portable(posix) way to check when running
from a symlink to lbmk in the current work directory

for example:

ln -s lbmk/build lbmktest
./lbmktest roms list

this would pass the new test, and first try to
include option.sh. in practise, the user probably  doesn't
happen to have include/option.sh in their current path

i can use readlink here, but again not portable

the current check will suffice. it also works when
the symlink is called from $PATH

e.g. /usr/bin/lbmktest exists and you do:
lbmktest roms list

Signed-off-by: Leah Rowe <leah@libreboot.org>

0 files changed, 0 insertions, 0 deletions