Remove -u root as mysql is executed with root user
Remove -u root as mysql is executed with root user

As openstack installation guides suggest to run mysql with root shell
user, mysql will not ask for password, so in
controller-install-*.rst "-u root -p" is useless.

Change-Id: I12807c72ee9fdbba6569e9b896bda22888c48a2d
Related-Bug: #1785025

openstack/barbican,openstack/barbican