qemu.tests.multi_disk: Fix bootindex bug

Fix signal_repeat variant to boot with the correct bootindex.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
virttest.qemu_qtree: Hook for ahci disks

AHCI disk is in reality ide-drive disk inside AHCI bus.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
REMOVEME: BZ 910359, gather info

run -t qemu --tests='multi_disk..virtio_scsi_variants..multi_lun' -g Fedora.18.x86_64 --smp=1 -m 4096 -v

grep for "RESULTS"

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>