[pr2eus] :go-pos-unsafe always returns nil in kinematics simualtion and cmd_vel case

[knorth55]

:go-pos-unsafe always returns nil in kinematics simulation or cmd_vel case. :go-pos-unsafe-no-wait returns t but :go-pos-unsafe-wait returns nil, thats why :go-pos-unsafe returns nil.

https://github.com/jsk-ros-pkg/jsk_pr2eus/blob/d2d28d27bab368d2195c99779591e77c24b42692/pr2eus/robot-interface.l#L1699-L1701

I supposed that :go-pos-unsafe should return t if the motion works correctly.

[knorth55]

:go-pos-unsafe only returns t or nil when move_base_trajectory_action is enable and the action succeeded to run the motion.