libxl: don't overwrite error from virNetSocketNewConnectTCP()
libxl: don't overwrite error from virNetSocketNewConnectTCP()

Remove redundant error reporting in libxlDomainMigrationPerform().
virNetSocketNewConnectTCP() is perfectly capable of reporting
sensible errors.

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