error "# mkdir('/..../qtest-9p-local-M33XsI') failed: File exists" on every run of 'qos-test'

Host environment

• Operating system: Fedora 35
• Architecture: x86_64
• QEMU flavor: qemu-system-x86_64
• QEMU version: git master 3d228a74

Description of problem

$ ./build//tests/qtest/qos-test -h
# mkdir('/home/berrange/src/virt/qemu/qtest-9p-local-qThj5y') failed: File exists
Usage:
  ./build//tests/qtest/qos-test [OPTION...]
...snip...

Notice the error message from 'mkdir()' whic appears every time you run this program.

Steps to reproduce

1. Run qos-test