soc: qcom: smem_state: Add refcounting for the 'state->of_node'

In qcom_smem_state_register() and qcom_smem_state_release(), we
should better use of_node_get() and of_node_put() for the reference
creation and destruction of 'device_node'.

Fixes: 9460ae2f ("soc: qcom: Introduce common SMEM state machine code")
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220721135217.1301039-2-windhl@126.com

drivers/soc/qcom/smem_state.c

@@ -136,6 +136,7 @@ static void qcom_smem_state_release(struct kref *ref)
 	struct qcom_smem_state *state = container_of(ref, struct qcom_smem_state, refcount);
 
 	list_del(&state->list);
+	of_node_put(state->of_node);
 	kfree(state);
 }
 
@@ -205,7 +206,7 @@ struct qcom_smem_state *qcom_smem_state_register(struct device_node *of_node,
 
 	kref_init(&state->refcount);
 
-	state->of_node = of_node;
+	state->of_node = of_node_get(of_node);
 	state->ops = *ops;
 	state->priv = priv;