[PATCH] futex: Apply recent futex fixes to futex_compat

The recent fixups in futex.c need to be applied to futex_compat.c too.  Fixes
a hang reported by Olaf.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>