tests/device-introspect: Test with all machines, not only with "none"

tests/device-introspect: Test with all machines, not only with "none"

Certain device introspection crashes used to only happen if you were
using a certain machine, e.g. if the machine was using serial_hd() or
nd_table[], and a device was trying to use these in its instance_init
function, too.

To be able to catch these problems, let's extend the device-introspect
test to check the devices on all machine types, with and without the
"-nodefaults" parameter (since this makes a difference sometimes, too).
Since this is a rather slow operation, and most of the problems are
already handled by testing with the "none" machine only, the test with
all machines is only run in the "make check SPEED=slow" mode.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1534419358-10932-8-git-send-email-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>