rgw: fix cephObjectStore failing with pre-existing pools

When attempting to use pre-existing (or cephBlockPool managed) pools and
the cephObjectStore.spec.{metadataPool,dataPool} fields are not
specified, rgw creation will fail with this error:

    2024-09-25 21:00:17.744358 E | ceph-object-controller: failed to reconcile CephObjectStore "rook-ceph/test1". failed to create object store deployments: failed to create object pools: failed to create metadata pools: failed to create pool "test1.rgw.control": pool "test1.rgw.control" type is not defined as replicated or erasure coded

Signed-off-by: Joshua Hoblitt <josh@hoblitt.com>
(cherry picked from commit 9b952e0a55)

pkg/operator/ceph/object/objectstore.go

@@ -767,6 +767,9 @@ func ConfigurePools(context *Context, cluster *cephv1.ClusterSpec, metadataPool,
 		if len(missingPools) > 0 {
 			return fmt.Errorf("CR store pools are missing: %v", missingPools)
 		}
+
+		// pools exist, nothing to do
+		return nil
 	}
 
 	// get the default PG count for rgw metadata pools