Hypervisor view builder's _collection_name,
'hypervisors' is used to build next link that
sdk use as uri to do paginated query. But correct
API should be `GET /v2.1/os-hypervisors?<params>`
rather than `GET /v2.1/hypervisors?<params>`.
This patch fixes this bug.
Change-Id: Idc4f3fe54136a6bd3dbc7dc0efd3f62745991199
Closes-Bug: 1864428
Signed-off-by: Fan Zhang <zh.f@outlook.com>