qemu: Fix qemuMonitorCreateObjectProps
qemu: Fix qemuMonitorCreateObjectProps

Fix the return value status comparison checking for call to
virJSONValueObjectCreateVArgs introduced by commit id f0a23c0c3.

If a NULL arglist is passed, then a 0 is returned which is a
valid status and we only should fail when the return is < 0.

This resolves an issue seen for "virsh iothreadadd $dom $iothread"
where a "error: An error occurred, but the cause is unknown" error
was generated when trying to hotplug an IOThread to a domain since
qemuDomainHotplugAddIOThread passes a NULL arglist.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

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