mtd: nand: Use scoped_guard for mutex in nand_resume

Refactor nand_resume() to use scoped_guard() instead of explicit
mutex_lock/unlock. This improves code safety by ensuring the mutex
is always released through the RAII-based cleanup infrastructure.

The behavior is functionally equivalent. The mutex is released at the
end of the scoped block, after which wake_up_all() is called to
preserve the original locking semantics.

Signed-off-by: Richard Lyu <richard.lyu@suse.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: r1chard-lyu

drivers/mtd/nand/raw/nand_base.c

@@ -43,6 +43,7 @@
 #include <linux/mtd/partitions.h>
 #include <linux/of.h>
 #include <linux/gpio/consumer.h>
+#include <linux/cleanup.h>
 
 #include "internals.h"
 
@@ -4704,16 +4705,16 @@ static void nand_resume(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 
-	mutex_lock(&chip->lock);
-	if (chip->suspended) {
-		if (chip->ops.resume)
-			chip->ops.resume(chip);
-		chip->suspended = 0;
-	} else {
-		pr_err("%s called for a chip which is not in suspended state\n",
-			__func__);
+	scoped_guard(mutex, &chip->lock) {
+		if (chip->suspended) {
+			if (chip->ops.resume)
+				chip->ops.resume(chip);
+			chip->suspended = 0;
+		} else {
+			pr_err("%s called for a chip which is not in suspended state\n",
+				__func__);
+		}
 	}
-	mutex_unlock(&chip->lock);
 
 	wake_up_all(&chip->resume_wq);
 }