Fix probing of QED file format
Fix probing of QED file format

The QED file format is non-versioned, so although the magic
value matched, libvirt rejected it due to lack of a version
number to compare against. We need to distinguish this case
by allowing a value of '-2' to indicate a non-versioned file
where only the magic is required to match

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

olafhering/libvirt,agx/libvirt,datto/libvirt,emaste/libvirt,trainstack/libvirt,agx/libvirt,emaste/libvirt,olafhering/libvirt,nertpinx/libvirt,nertpinx/libvirt,rlaager/libvirt,iam-TJ/libvirt,agx/libvirt,trainstack/libvirt,siboulet/libvirt-openvz,trainstack/libvirt,VenkatDatta/libvirt,iam-TJ/libvirt,jardasgit/libvirt,taget/libvirt,shugaoye/libvirt,libvirt/libvirt,bjzhang/libvirt,VenkatDatta/libvirt,cbosdo/libvirt,shugaoye/libvirt,agx/libvirt,cbosdo/libvirt,datto/libvirt,fabianfreyer/libvirt,crobinso/libvirt,libvirt/libvirt,eskultety/libvirt,andreabolognani/libvirt,datto/libvirt,elmarco/libvirt,crobinso/libvirt,zippy2/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,rlaager/libvirt,iam-TJ/libvirt,bjzhang/libvirt,jfehlig/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,iam-TJ/libvirt,olafhering/libvirt,crobinso/libvirt,zippy2/libvirt,bjzhang/libvirt,elmarco/libvirt,bjzhang/libvirt,cbosdo/libvirt,olafhering/libvirt,zhlcindy/libvirt-1.1.4-maintain,siboulet/libvirt-openvz,shugaoye/libvirt,andreabolognani/libvirt,eskultety/libvirt,iam-TJ/libvirt,libvirt/libvirt,rlaager/libvirt,iam-TJ/libvirt,taget/libvirt,trainstack/libvirt,taget/libvirt,eskultety/libvirt,siboulet/libvirt-openvz,taget/libvirt,elmarco/libvirt,taget/libvirt,elmarco/libvirt,zhlcindy/libvirt-1.1.4-maintain,datto/libvirt,nertpinx/libvirt,andreabolognani/libvirt,jfehlig/libvirt,trainstack/libvirt,VenkatDatta/libvirt,siboulet/libvirt-openvz,jardasgit/libvirt,fabianfreyer/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,datto/libvirt,siboulet/libvirt-openvz,elmarco/libvirt,rlaager/libvirt,emaste/libvirt,emaste/libvirt,jardasgit/libvirt,emaste/libvirt,nertpinx/libvirt,zippy2/libvirt,rlaager/libvirt,libvirt/libvirt,iam-TJ/libvirt,zippy2/libvirt,fabianfreyer/libvirt,zhlcindy/libvirt-1.1.4-maintain,zhlcindy/libvirt-1.1.4-maintain,trainstack/libvirt,jfehlig/libvirt,shugaoye/libvirt,cbosdo/libvirt,bjzhang/libvirt,emaste/libvirt,VenkatDatta/libvirt,zhlcindy/libvirt-1.1.4-maintain,jardasgit/libvirt,trainstack/libvirt,cbosdo/libvirt,agx/libvirt,emaste/libvirt,eskultety/libvirt,crobinso/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,eskultety/libvirt