exit with status 1 if help is called on an invalid command.
exit with status 1 if help is called on an invalid command.

Signed-off-by: Daniel Nephin <6347c07ae509164cffebfb1e2a0d6ed64958db19@docker.com>

dnephin/cli,redpanda/cli,thaJeztah/cli,riyazdf/cli,allencloud/cli,docker/cli,ashfall/cli,docker/cli,dnephin/cli,ashfall/cli,cpuguy83/cli,gdevillele/cli,redpanda/cli,allencloud/cli,thaJeztah/cli,e11137/cli,e11137/cli,cpuguy83/cli,Zebrilee/cli,Zebrilee/cli,riyazdf/cli