usb: gadget: udc-core: fix bug on soft_connect interface

We should not be using dev_get_drvdata() because we
never call dev_set_drvdata(). Let's use container_of()
as all other sysfs attributes.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/udc-core.c

@@ -356,7 +356,7 @@ static DEVICE_ATTR(srp, S_IWUSR, NULL, usb_udc_srp_store);
 static ssize_t usb_udc_softconn_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t n)
 {
-	struct usb_udc		*udc = dev_get_drvdata(dev);
+	struct usb_udc		*udc = container_of(dev, struct usb_udc, dev);
 
 	if (sysfs_streq(buf, "connect")) {
 		usb_gadget_connect(udc->gadget);