i2c: rk3x: report number of messages transmitted

commit c6cbfb91 upstream.

master_xfer() method should return number of i2c messages transferred,
but on Rockchip we were usually returning just 1, which caused trouble
with users that actually check number of transferred messages vs.
checking for negative error codes.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/i2c/busses/i2c-rk3x.c

@@ -588,7 +588,7 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
 	clk_disable(i2c->clk);
 	spin_unlock_irqrestore(&i2c->lock, flags);
 
-	return ret;
+	return ret < 0 ? ret : num;
 }
 
 static u32 rk3x_i2c_func(struct i2c_adapter *adap)