daemon/cluster: fix unused context (staticcheck)
```
daemon/cluster/nodes.go:69:36: SA4009: argument ctx is overwritten before first use (staticcheck)
13:06:14 	return c.lockedManagerAction(func(ctx context.Context, state nodeState) error {
```
@@ -66,7 +66,7 @@ func (c *Cluster) GetNode(input string) (types.Node, error) {
// UpdateNode updates existing nodes properties.
func (c *Cluster) UpdateNode(input string, version uint64, spec types.NodeSpec) error {
- return c.lockedManagerAction(func(ctx context.Context, state nodeState) error {
+ return c.lockedManagerAction(func(_ context.Context, state nodeState) error {
nodeSpec, err := convert.NodeSpecToGRPC(spec)
if err != nil {
return errdefs.InvalidParameter(err)
