kprobes, notifier: Use NOKPROBE_SYMBOL macro in notifier

Use NOKPROBE_SYMBOL macro to protect functions from
kprobes instead of __kprobes annotation in notifier.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20140417081835.26341.56128.stgit@ltc230.yrl.intra.hitachi.co.jp


Signed-off-by: Ingo Molnar <mingo@kernel.org>