mtd: mtdconcat: map: remove redundant assignment to variable 'size'

Variable 'size' is being assigned the value zero that will never be
read. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200910154451.752569-1-colin.king@canonical.com

Author: Colin Ian King

drivers/mtd/mtdconcat.c

@@ -114,7 +114,6 @@ concat_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 		size_t size, retsize;
 
 		if (to >= subdev->size) {
-			size = 0;
 			to -= subdev->size;
 			continue;
 		}