i2c: mux: make use of __i2c_smbus_xfer

Calling the __i2c_smbus_xfer wrapper in __i2c_mux_smbus_xfer provides
retries and thus makes the parent-locked case consistent with the both
mux-locked (i2c_mux_smbus_xfer) and the I2C transfer cases.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/i2c-mux.c

@@ -87,7 +87,7 @@ static int __i2c_mux_smbus_xfer(struct i2c_adapter *adap,
 
 	ret = muxc->select(muxc, priv->chan_id);
 	if (ret >= 0)
-		ret = parent->algo->smbus_xfer(parent, addr, flags,
+		ret = __i2c_smbus_xfer(parent, addr, flags,
 				       read_write, command, size, data);
 	if (muxc->deselect)
 		muxc->deselect(muxc, priv->chan_id);