KVM test: Enable the serial console for all linux guests

As we have the ability to dump the content from serial console or use
a session through it, we need to redirect the console to serial
through unattended files to make use of it. The patch also keep the
tty0 accroding to the suggestion of Michael Goldish.

Signed-off-by: Jason Wang <jasowang@redhat.com>


git-svn-id: http://test.kernel.org/svn/autotest/trunk@4671 592f7852-d20e-0410-864c-8624ca9c26a4
11 files changed