Revert "exec: silence hugetlbfs warning under qtest"

This reverts commit 1c7ba94a184df1eddd589d5400d879568d3e5d08.

That commit changed QEMU initialization order from

 - object-initial, chardev, qtest, object-late

to

 - chardev, qtest, object-initial, object-late

This breaks chardev setups which need to rely on objects
having been created. For example, when chardevs use TLS
encryption in the future, they need to have tls credential
objects created first.

This revert, restores the ordering introduced in

  commit f08f9271bfe3f19a5eb3d7a2f48532065304d5c8
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Wed May 13 17:14:04 2015 +0100

    vl: Create (most) objects before creating chardev backends

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1448448749-1332-2-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
