Added missing decorator for instance.create.error
Added missing decorator for instance.create.error

The decorator for instance.create.error was forgotten to add.
Because of this, documentation and sample was not generated for
the instance.create.error notification.

Change-Id: I899acdd24e1378200fa16cbc5bc9a0419aef87ea

jianghuaw/nova,gooddata/openstack-nova,rajalokan/nova,rahulunair/nova,gooddata/openstack-nova,rahulunair/nova,klmitch/nova,mahak/nova,Juniper/nova,Juniper/nova,klmitch/nova,mikalstill/nova,rajalokan/nova,phenoxim/nova,openstack/nova,klmitch/nova,gooddata/openstack-nova,mikalstill/nova,rajalokan/nova,openstack/nova,openstack/nova,mikalstill/nova,jianghuaw/nova,jianghuaw/nova,Juniper/nova,rajalokan/nova,mahak/nova,vmturbo/nova,phenoxim/nova,vmturbo/nova,vmturbo/nova,rahulunair/nova,jianghuaw/nova,vmturbo/nova,gooddata/openstack-nova,mahak/nova,Juniper/nova,klmitch/nova