qemu: qemuDomainObjClearJob: use g_clear_pointer
qemu: qemuDomainObjClearJob: use g_clear_pointer

The function used g_clear_pointer for all but one pointer.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

libvirt/libvirt,libvirt/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt,nertpinx/libvirt,nertpinx/libvirt,jardasgit/libvirt,crobinso/libvirt,nertpinx/libvirt,jfehlig/libvirt,crobinso/libvirt,olafhering/libvirt,jardasgit/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,zippy2/libvirt,jardasgit/libvirt,nertpinx/libvirt,crobinso/libvirt,jfehlig/libvirt,jardasgit/libvirt,zippy2/libvirt,jardasgit/libvirt,crobinso/libvirt,zippy2/libvirt,olafhering/libvirt