The test scripts support a "req" directive which requires one test script
to be run before another. It's implemented by doing a topological sort
based on these directives in the runner scripts, which is about as awkward
as you'd expect in Bourne shell.
It turns out we only use this functionality in one place - to make the
"make install" test run after the plain "make" test. We also already have
a simpler way of making sure tests run in a specific order: just put them
into the same test script file.
So, remove support for the "req" directive and just fold the build/all and
build/install test scripts together.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>