qemu.tests.multi_disk_random_hotplug: Fix DeviceInsertError location

DeviceInsertError is currently located in qemu_devices.utils.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
virttest.qemu_devices: Fix incorrect scsi-id name

autotest scsiid property is called 'scsi-id' in qemu.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
virttest.qemu_deivces: Fix bus checking when single 'type' is used

With support for list-of-type-matching the support for
single-type-matching stopped working, which sometimes lead to the problem
with devices ending in buses correct according to qemu, but incorrect
according to autotest. This patch returns the original behavior in the
single-type-matching cases.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Merge pull request #1280 from ldoktor/add_device

virttest.qemu_devices: Couple of hot-fixes