[PATCH] asm/semaphore.h compatibility header

Not really a patch....

Here's an asm/semaphore.h compatibility header to help build Comedi 
drivers for kernel versions prior to 2.2.18.  It defines the following 
missing macros:

   init_MUTEX(x)
   init_MUTEX_LOCKED(x)
   DECLARE_MUTEX(name)
   DECLARE_MUTEX_LOCKED(name)

I didn't define sema_init(sem, val) as I the implementation is 
arch-dependent.

The only drivers that use mutexes currently are usbdux and usbduxfast, 
and they won't compile for old kernels anyway.  Still, there's no reason 
why some other drivers couldn't make use of mutexes now!

-- 
-=( Ian Abbott _at_ MEV Ltd.    E-mail: <abbotti_at_mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-