driver core: dev_get_drvdata: Don't check for NULL dev

There is no point in calling dev_get_drvdata without a valid device.
So checking for dev == NULL is pointless. If such a check is ever
needed - which I doubt - the driver should do it before calling
dev_get_drvdata.

We were returning NULL if dev was NULL, which the caller certainly did
not expect anyway, so that was only delaying the crash if the caller
is not paying attention.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/dd.c

@@ -594,9 +594,7 @@ void driver_detach(struct device_driver *drv)
  */
 void *dev_get_drvdata(const struct device *dev)
 {
-	if (dev)
-		return dev->driver_data;
-	return NULL;
+	return dev->driver_data;
 }
 EXPORT_SYMBOL(dev_get_drvdata);