Input: rotary_encoder - fix relative axis support

When the rotart_encoder driver is used to report relative axis
information the "steps" in the platform data could be missing
since it's not relevant.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/misc/rotary_encoder.c

@@ -106,8 +106,8 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
 	struct input_dev *input;
 	int err;
 
-	if (!pdata || !pdata->steps) {
-		dev_err(&pdev->dev, "invalid platform data\n");
+	if (!pdata) {
+		dev_err(&pdev->dev, "missing platform data\n");
 		return -ENOENT;
 	}