[PATCH vfs-2.6 5/6] vfs: remove LOOKUP_PARENT from non LOOKUP_PARENT lookup

lookup_hash() with LOOKUP_PARENT is bogus. And this prepares to add
new intent on those path.

The user of LOOKUP_PARENT intent is nfs only, and it checks whether
nd->flags has LOOKUP_CREATE or LOOKUP_OPEN, so the result is same.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>