mtd: onenand: samsung: remove set but not used variable

Fixes gcc '-Wunused-but-set-variable' warning:
drivers/mtd/nand/onenand/samsung_mtd.c: In function s3c_onenand_check_lock_status:
drivers/mtd/nand/onenand/samsung_mtd.c:731:6: warning: variable tmp set but not used [-Wunused-but-set-variable]

Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/drivers/mtd/nand/onenand/samsung_mtd.c b/drivers/mtd/nand/onenand/samsung_mtd.c
index beb7987..d61317a 100644
--- a/drivers/mtd/nand/onenand/samsung_mtd.c
+++ b/drivers/mtd/nand/onenand/samsung_mtd.c
@@ -728,13 +728,12 @@ static void s3c_onenand_check_lock_status(struct mtd_info *mtd)
 	struct onenand_chip *this = mtd->priv;
 	struct device *dev = &onenand->pdev->dev;
 	unsigned int block, end;
-	int tmp;
 
 	end = this->chipsize >> this->erase_shift;
 
 	for (block = 0; block < end; block++) {
 		unsigned int mem_addr = onenand->mem_addr(block, 0, 0);
-		tmp = s3c_read_cmd(CMD_MAP_01(onenand, mem_addr));
+		s3c_read_cmd(CMD_MAP_01(onenand, mem_addr));
 
 		if (s3c_read_reg(INT_ERR_STAT_OFFSET) & LOCKED_BLK) {
 			dev_err(dev, "block %d is write-protected!\n", block);