tests: replace --enable-docker with --enable-root-make-check

tests: replace --enable-docker with --enable-root-make-check

The --enable-docker logic was that each test that needs privileges to
run uses a container to do so. The problem with this approach and
make -j8 check is that such tests compete for a single container.

The --enable-root-make-check activates tests that require privileges and
assume it is ok to use sudo to acquire privileges. The decision to run
in a container is then taken by the caller who will run something like:

   docker-tests.sh ./configure --enable-root-make-check
   docker-tests.sh make -j8 check

Signed-off-by: Loic Dachary <ldachary@redhat.com>