[SERIAL] 8250_early.c passing 0 instead of NULL

Fix sparse warning about passing `0` to simple_strtoul()

Signed-off-by: Ben Dooks <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

drivers/serial/8250_early.c

···
 
 	if ((options = strchr(options, ','))) {
 		options++;
-		device->baud = simple_strtoul(options, 0, 0);
+		device->baud = simple_strtoul(options, NULL, 0);
 		length = min(strcspn(options, " "), sizeof(device->options));
 		strncpy(device->options, options, length);
 	} else {