soc: qcom: smem_state: simplify locking with guard()

Simplify error handling (less gotos) over locks with guard().

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/soc/qcom/smem_state.c

···
  * Copyright (c) 2015, Sony Mobile Communications Inc.
  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
  */
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/module.h>
···
 {
 	struct qcom_smem_state *state;
 
-	mutex_lock(&list_lock);
+	guard(mutex)(&list_lock);
 
 	list_for_each_entry(state, &smem_states, list) {
 		if (state->of_node == np) {
 			kref_get(&state->refcount);
-			goto unlock;
+			return state;
 		}
 	}
-	state = ERR_PTR(-EPROBE_DEFER);
-
-unlock:
-	mutex_unlock(&list_lock);
-
-	return state;
+	return ERR_PTR(-EPROBE_DEFER);
 }
 
 /**