rcu: Remove lockdep annotations from RCU's _notrace() API members

The lockdep annotations rcu_read_acquire() and rcu_read_release()
might lead to infinite looping if called from lockdep.  So this patch
removes them.  Formal repost of http://lkml.org/lkml/2009/8/25/309
on the strength of Lai Jiangshan's review.

Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <20090826015337.GA18904@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>