rcu: Fix comment for rcu_dereference_raw_notrace

rcu_dereference_raw() calls indirectly rcu_read_lock_held() while
rcu_dereference_raw_notrace() does not so fix the comment about the latter.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

include/linux/rcupdate.h

@@ -741,7 +741,7 @@ static inline void rcu_preempt_sleep_check(void)
  * The tracing infrastructure traces RCU (we want that), but unfortunately
  * some of the RCU checks causes tracing to lock up the system.
  *
- * The tracing version of rcu_dereference_raw() must not call
+ * The no-tracing version of rcu_dereference_raw() must not call
  * rcu_read_lock_held().
  */
 #define rcu_dereference_raw_notrace(p) __rcu_dereference_check((p), 1, __rcu)