USB: Phidget: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().  It fixes all 3 phidget drivers, which all have
the same problem.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sean Young <sean@mess.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/misc/phidgetservo.c b/drivers/usb/misc/phidgetservo.c
index 7d590c0..1ca7ddb 100644
--- a/drivers/usb/misc/phidgetservo.c
+++ b/drivers/usb/misc/phidgetservo.c
@@ -275,14 +275,14 @@
         } while (value);
 	dev->dev_no = bit;
 
-	dev->dev = device_create(phidget_class, &dev->udev->dev, 0,
-				 "servo%d", dev->dev_no);
+	dev->dev = device_create_drvdata(phidget_class, &dev->udev->dev,
+					 MKDEV(0, 0), dev,
+					 "servo%d", dev->dev_no);
 	if (IS_ERR(dev->dev)) {
 		rc = PTR_ERR(dev->dev);
 		dev->dev = NULL;
 		goto out;
 	}
-	dev_set_drvdata(dev->dev, dev);
 
 	servo_count = dev->type & SERVO_COUNT_QUAD ? 4 : 1;