[IA64] fix ia64 is_hugepage_only_range

fix is_hugepage_only_range() definition to be "overlaps"
instead of "within architectural restricted hugetlb address
range".  Simplify the ia64 specific code that used to use
is_hugepage_only_range() to just check which region the
address is in.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>