From: David Mosberger <davidm@napali.hpl.hp.com>,
	"Sharma, Arun" <arun.sharma@intel.com>

The truncate race fix assumed that a non-zero vma->vm_ops->nopage implies a
non-zero vma->vm_file.

The ia64 x86 emulation code breaks this assumption, so teach do_no_page() to
handle it.