Correct affinity spec.

kubernetes/apps/rook-ceph/rook-ceph/cluster/helmrelease.yaml

@@ -39,17 +39,20 @@ spec:
       bdev_async_discard = true
 
     cephClusterSpec:
+      mon:
+        count: 3
       network:
         provider: host
       placement:
         mon:
-          affinity:
           nodeAffinity:
             requiredDuringSchedulingIgnoredDuringExecution:
               nodeSelectorTerms:
                 - matchExpressions:
-                      - key: node-role.kubernetes.io/control-plane
-                        operator: Exists
+                  - key: role
+                    operator: In
+                    values:
+                    - storage-node