Fix ulimit command form
Fix ulimit command form

The ulimit is builtin, so we need shell form to execute it.

Signed-off-by: Kai Qiang Wu(Kennan) <03a9957f0460ce3379f6e452396aa35e108b5af5@cn.ibm.com>

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