[api] Rename the hostname param to hostid
[api] Rename the hostname param to hostid

Just change the name of the param and the comments. Simple change.
Will be tested by systest.

justinhayes/cm_api,cloudera/cm_api,cdapio/cm_api,cdapio/cm_api,cdapio/cm_api,cdapio/cm_api,cloudera/cm_api,justinhayes/cm_api,cloudera/cm_api,justinhayes/cm_api