i2c: arb: gpio-challenge: stop double error reporting

i2c_mux_add_adapter already logs a message on failure.
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>

drivers/i2c/muxes/i2c-arb-gpio-challenge.c

@@ -202,10 +202,8 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 
 	/* Actually add the mux adapter */
 	ret = i2c_mux_add_adapter(muxc, 0, 0, 0);
-	if (ret) {
-		dev_err(dev, "Failed to add adapter\n");
+	if (ret)
 		i2c_put_adapter(muxc->parent);
-	}
 
 	return ret;
 }