m68k: Skip futex_atomic_cmpxchg_inatomic() test

Skip the futex_atomic_cmpxchg_inatomic() test in futex_init(). It causes a 
fatal exception on 68030 (and presumably 68020 also).

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1403061006440.5525@nippy.intranet


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>