sched/wait: Fix wait_event_freezable() documentation

I noticed the comment label 'wait_event' was wrong.

Signed-off-by: Stafford Horne <shorne@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1456234768-24933-1-git-send-email-shorne@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/wait.h

@@ -338,7 +338,7 @@ do {									\
 			    schedule(); try_to_freeze())
 
 /**
- * wait_event - sleep (or freeze) until a condition gets true
+ * wait_event_freezable - sleep (or freeze) until a condition gets true
  * @wq: the waitqueue to wait on
  * @condition: a C expression for the event to wait for
  *