Switch to using a comprehension for process_names. (#614)
Switch to using a comprehension for process_names. (#614)

Newer versions of flake8-comprehenstion complain about this
usage, and the new code should be backwards compatible and
faster to boot.

Signed-off-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@openrobotics.org>
ros2/launch,ros2/launch,ros2/launch