x86, mm: Correct vmflag test for checking VM_HUGETLB

x86, mm: Correct vmflag test for checking VM_HUGETLB

commit 27987a92bb1a105dab251728fac50539c7e66deb('enable tlb flush range
support for x86') change flush_tlb_mm_range() considerably. After this,
we test whether vmflag equal to VM_HUGETLB and it may be always failed,
because vmflag usually has other flags simultaneously.
Our intention is to check whether this vma is for hughtlb, so correct it
according to this purpose.

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Acked-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1352740656-19417-1-git-send-email-js1304@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>