i2c: fix always-true condition in i2c_probe_chip()

Per dm_i2c_ops.probe_chip documentation, i2c_probe_chip() shall fallback
to default probe method when .probe_chip() returns -ENOSYS.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Heiko Schocher <hs@denx.de>

drivers/i2c/i2c-uclass.c

@@ -280,7 +280,7 @@ static int i2c_probe_chip(struct udevice *bus, uint chip_addr,
 
 	if (ops->probe_chip) {
 		ret = ops->probe_chip(bus, chip_addr, chip_flags);
-		if (!ret || ret != -ENOSYS)
+		if (ret != -ENOSYS)
 			return ret;
 	}