utils: fix segfault in iwinfo_hardware_id_from_mtd()

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

iwinfo_utils.c

@@ -177,8 +177,8 @@ int iwinfo_hardware_id_from_mtd(struct iwinfo_hardware_id *id)
 	FILE *mtd;
 	uint16_t *bc;
 
-	int fd;
-	unsigned int len, off;
+	int fd, off;
+	unsigned int len;
 	char buf[128];
 
 	if (!(mtd = fopen("/proc/mtd", "r")))
@@ -186,7 +186,7 @@ int iwinfo_hardware_id_from_mtd(struct iwinfo_hardware_id *id)
 
 	while (fgets(buf, sizeof(buf), mtd) != NULL)
 	{
-		if (fscanf(mtd, "mtd%u: %x %*x %127s", &off, &len, buf) < 3 ||
+		if (fscanf(mtd, "mtd%d: %x %*x %127s", &off, &len, buf) < 3 ||
 		    (strcmp(buf, "\"boardconfig\"") && strcmp(buf, "\"EEPROM\"") &&
 		     strcmp(buf, "\"factory\"")))
 		{