qemu: Fix starting a domain with corrupted managed save file
qemu: Fix starting a domain with corrupted managed save file

Commit v3.4.0-44-gac793bd71 fixed a memory leak, but failed to return
the special -3 value. Thus an attempt to start a domain with corrupted
managed save file would removed the corrupted file and report
"An error occurred, but the cause is unknown" instead of starting the
domain from scratch.

https://bugzilla.redhat.com/show_bug.cgi?id=1460962

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