Fix some typos in kernel/trace.

Link: http://lkml.kernel.org/r/1343887320.2228.9.camel@louis-ThinkPad-T410Signed-off-by: NWang Tianhong <wangthbj@linux.vnet.ibm.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>