mtd: cfi_cmdset_0002: check return code for get_chip()

Coverity CID 1230633
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Christian Riesch <christian.riesch@omicron.at>

drivers/mtd/chips/cfi_cmdset_0002.c

@@ -1434,6 +1434,10 @@ static int cfi_amdstd_otp_walk(struct mtd_info *mtd, loff_t from, size_t len,
 
 				mutex_lock(&chip->mutex);
 				ret = get_chip(map, chip, base, FL_LOCKING);
+				if (ret) {
+					mutex_unlock(&chip->mutex);
+					return ret;
+				}
 
 				/* Enter lock register command */
 				cfi_send_gen_cmd(0xAA, cfi->addr_unlock1,