rcu-tasks: Clarify the cblist_init_generic() function's pr_info() output

This commit uses rtp->name instead of __func__ and outputs the value
of rcu_task_cb_adjust, thus reducing console-log output.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>