IMPALA-970 The kinit renewal command should specify the credential cache file.

All Impala services store their kerberos ticket credentials in a custom file. This
PATCH updates the ticket renewal command to use the custom credentials file.

Change-Id: I4a77a9b58e9747c0c73fa7a53a85e1214c7a31f7
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2409
Reviewed-by: Henry Robinson <henry@cloudera.com>
Reviewed-by: Ishaan Joshi <ishaan@cloudera.com>
Tested-by: jenkins
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2413