mem_access: fix setting default mem_access type

mem_access: fix setting default mem_access type

When xc_hvm_set_mem_access(xch, domain_id, default_access, ~0ull, 0)
is called, first_pfn=~0ull is a hint to HVMOP_set_mem_access as to
what the default mem_access type is for the domain. This call was
failing because it was gated by the memory range check in the
HVMOP_set_mem_access case statement in do_hvm_op(). The following
patch fixes this issue.

Signed-off-by: Aravindh Puthiyaparambil <aravindh@virtuata.com>
Acked-by: Tim Deegan <tim@xen.org>
Committed-by: Tim Deegan <tim@xen.org>
---
 xen/arch/x86/hvm/hvm.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)