b716395e added code to handle
a compatability issue with 32bit quota tools, but the new compat
routines are only needed when CONFIG_COMPAT=y (and with this set
to 'n' there are compilation problems since some new typedefs are
not visible).

Reported by Doug Chapman.  Fix tuned by a cast of thousands (Andi,
Andreas, Arthur, HPA, Willy)
Signed-off-by: Tony Luck <tony.luck@intel.com>