mgr/rook: prevent creation of NFS clusters not in .nfs rados pool

This commit prevents the creation of NFS clusters that don't use the
.nfs RADOS pool using ceph orch apply nfs.

Signed-off-by: Joseph Sawaya <jsawaya@redhat.com>

src/pybind/mgr/rook/module.py

@@ -31,7 +31,7 @@ def names(self: Any, names: Any) -> None:
     client = None
     config = None
 
-from mgr_module import MgrModule, Option
+from mgr_module import MgrModule, Option, NFS_POOL_NAME
 import orchestrator
 from orchestrator import handle_orch_error, OrchResult, raise_if_exception
 
@@ -335,6 +335,8 @@ def describe_service(self,
                 "cephnfses/")
             self.log.warning('CephNFS %s' % all_nfs)
             for nfs in all_nfs.get('items', []):
+                if nfs['spec']['rados']['pool'] != NFS_POOL_NAME:
+                    continue
                 nfs_name = nfs['metadata']['name']
                 svc = 'nfs.' + nfs_name
                 if svc in spec: