Replace `RCLCPP_ERROR_STREAM` with `RCLCPP_ERROR` in gripper action controller

[bmagyar]

Could we also change this macro to RCLCPP_ERROR instead of stream? There is no value in it, but it's confusing to read.

I know I am asking for something out of scope, but it seems there are only three places of this and it would be great to solve them right away.

Originally posted by @destogl in #329 (comment)

[christophfroehlich]

https://github.com/search?q=repo%3Aros-controls%2Fros2_controllers%20RCLCPP_ERROR_STREAM&type=code

[Vedant87]

Hello, I would like to contribute. To which branch should I open a PR ?

[christophfroehlich]

please target the master branch, we will then backport this