disable/enable a service has no output

When disable/enable a cinder service, there is no output, this
caused end user does not know if the service was disabled/enabled
successfully.

It is better add some output for the command just like nova to tell
end user the service status.

Change-Id: I9d440ab7437c268b17627e255f152db0b3bf4f53
Closes-Bug: #1261120
Merge "disable/enable a service has no output"