tests: cleanup qemuxml2argvtest
tests: cleanup qemuxml2argvtest

This removes the testFailed magic and makes the code more readable.

Signed-off-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>

jfehlig/libvirt,datto/libvirt,nertpinx/libvirt,datto/libvirt,andreabolognani/libvirt,libvirt/libvirt,nertpinx/libvirt,eskultety/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,olafhering/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,crobinso/libvirt,olafhering/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,taget/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,taget/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,datto/libvirt,libvirt/libvirt,libvirt/libvirt,eskultety/libvirt,crobinso/libvirt,olafhering/libvirt,andreabolognani/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,eskultety/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,eskultety/libvirt,taget/libvirt,datto/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,zippy2/libvirt,nertpinx/libvirt,andreabolognani/libvirt,zippy2/libvirt,datto/libvirt,zippy2/libvirt,jardasgit/libvirt,libvirt/libvirt,taget/libvirt,taget/libvirt,jardasgit/libvirt,jfehlig/libvirt,zippy2/libvirt,eskultety/libvirt,crobinso/libvirt