libvirt-domain: fix no error report when p2p migrate fail
libvirt-domain: fix no error report when p2p migrate fail

After commit a26669d7, we only jump to error when
virDomainMigrateUnmanagedParams return a value less than -1.
this will make the migrate result always be success even we
meet some problem.

Signed-off-by: Luyao Huang <23d9981432efa88691fd2a71f5525bc2174f7664@redhat.com>

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