IPMI: remove bogus semaphore from watchdog

Lockdep was giving an error when loading the IPMI watchdog module.  It turns
out that if you try to claim a lock in a parameter handling routine, lockdep
won't see that lock as "static" yet because the module is not yet on the
module list, so it will complain.

However, the semaphore in question is completely unnecessary.  So just remove
it.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>