locking, semaphores: Annotate inner lock as raw

There is no reason to have the spin_lock protecting the semaphore
preemptible on -rt. Annotate it as a raw_spinlock.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

( On rt this also solves lockdep complaining about the
  rt_mutex.wait_lock being not initialized. )

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/semaphore.h

@@ -14,14 +14,14 @@
 
 /* Please don't access any members of this structure directly */
 struct semaphore {
-	spinlock_t		lock;
+	raw_spinlock_t		lock;
 	unsigned int		count;
 	struct list_head	wait_list;
 };
 
 #define __SEMAPHORE_INITIALIZER(name, n)				\
 {									\
-	.lock		= __SPIN_LOCK_UNLOCKED((name).lock),		\
+	.lock		= __RAW_SPIN_LOCK_UNLOCKED((name).lock),	\
 	.count		= n,						\
 	.wait_list	= LIST_HEAD_INIT((name).wait_list),		\
 }