[IA64] fix relinquish_memory()

[IA64] fix relinquish_memory()

This patch fixes the following panic.

(XEN) Assertion 'entry->prev->next == entry' failed, line 170, file xen-unstable.hg/xen/include/xen/list.h
(XEN) Xen BUG at xen-unstable.hg/xen/include/xen/list.h:170
(XEN) FIXME: implement ia64 dump_execution_state()
(XEN)
(XEN) Call Trace:
(XEN)  [<f400000004104670>] show_stack+0x90/0xb0
(XEN)                                 sp=f0000002f64cfbf0 bsp=f0000002f64c9918
(XEN)  [<f400000004105180>] dump_stack+0x30/0x50
(XEN)                                 sp=f0000002f64cfdc0 bsp=f0000002f64c98f8
(XEN)  [<f400000004064ac0>] __bug+0x70/0xa0
(XEN)                                 sp=f0000002f64cfdc0 bsp=f0000002f64c98c8
(XEN)  [<f400000004031290>] free_domheap_pages+0x380/0x700
(XEN)                                 sp=f0000002f64cfdc0 bsp=f0000002f64c9868
(XEN)  [<f4000000040ac470>] domain_page_flush_and_put+0x1c0/0x550
(XEN)                                 sp=f0000002f64cfdc0 bsp=f0000002f64c9820
(XEN)  [<f4000000040ac990>] domain_put_page+0x190/0x530
(XEN)                                 sp=f0000002f64cfdd0 bsp=f0000002f64c97b0
(XEN)  [<f4000000040ad060>] zap_domain_page_one+0x330/0x530
(XEN)                                 sp=f0000002f64cfde0 bsp=f0000002f64c9710
(XEN)  [<f4000000040ad570>] dom0vp_zap_physmap+0x70/0xe0
(XEN)                                 sp=f0000002f64cfdf0 bsp=f0000002f64c96d8
(XEN)  [<f4000000040838f0>] do_dom0vp_op+0x320/0x7b0
(XEN)                                 sp=f0000002f64cfdf0 bsp=f0000002f64c9690
(XEN)  [<f400000004002e60>] fast_hypercall+0x170/0x310
(XEN)                                 sp=f0000002f64cfe00 bsp=f0000002f64c9690
(XEN)
(XEN) ****************************************
(XEN) Panic on CPU 2:
(XEN) Xen BUG at xen-unstable.hg/xen/include/xen/list.h:170
(XEN) ****************************************
(XEN)
(XEN) Reboot in five seconds...
(XEN) Debugging connection not set up.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>