KVM: PPC: Book3S HV: Use list_move_tail instead of list_del/list_add_tail

Using list_move_tail() instead of list_del() + list_add_tail().

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>