Wait for hotunplug event to ensure device removed successfully

[yafu-1]

No description provided.

[yafu-1]

Test result:
$ /usr/local/bin/avocado run --vt-type libvirt --test-runner=runner --vt-machine-type arm64-mmio virtual_disks.discard_no_unref.hotplug_disk.enable.with_discard_unmap.file_disk --vt-connect-uri qemu:///system
No python imaging library installed. Screendump and Windows guest BSOD detection are disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
No python imaging library installed. PPM image conversion to JPEG disabled. In order to enable it, please install python-imaging or the equivalent for your distro.
JOB ID : 7d9c8c41c7fab9bef9d65f41ad7d718192b21edb
JOB LOG : /var/log/avocado/job-results/job-2024-09-11T08.27-7d9c8c4/job.log
(1/1) type_specific.io-github-autotest-libvirt.virtual_disks.discard_no_unref.hotplug_disk.enable.with_discard_unmap.file_disk: PASS (40.49 s)
RESULTS : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB HTML : /var/log/avocado/job-results/job-2024-09-11T08.27-7d9c8c4/results.html
JOB TIME : 41.14 s