tracing: Fix set_named_trigger_data() kernel-doc comment

Fix the description of the parameters.

Link: https://lkml.kernel.org/r/20210515105735.52785-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>