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>
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index c806fbf..3b9f588 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -106,8 +106,8 @@
 	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;
 	}