[IA64] fix p2m conversion for HVM domain case.

fix p2m conversion function, lookup_domain_mpa().
The access to the area where no device is assigned is properly
emulated for HVM domain case.
So lookup_domain_mpa() should return INVALID_MFN for HVM domain case
even when no p2m entry is allocated.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r 96b308cf9b0d xen/arch/ia64/xen/mm.c
--- a/xen/arch/ia64/xen/mm.c	Fri May 09 17:17:15 2008 +0900
+++ b/xen/arch/ia64/xen/mm.c	Fri May 09 17:21:48 2008 +0900
@@ -821,9 +821,11 @@
             if (entry != NULL)
                 p2m_entry_set(entry, pte, tmp_pte);
             return pte_val(tmp_pte);
-        } else if (is_hvm_domain(d))
-            return INVALID_MFN;
+        }
     }
+
+    if (is_hvm_domain(d))
+        return INVALID_MFN;
 
     if (mpaddr < d->arch.convmem_end && !d->is_dying) {
         gdprintk(XENLOG_WARNING, "vcpu %d iip 0x%016lx: non-allocated mpa "