usb gadget: don't save bind callback in struct usb_gadget_driver

To accomplish this the function to register a gadget driver takes the bind
function as a second argument.  To make things clearer rename the function
to resemble platform_driver_probe.

This fixes many section mismatches like

	WARNING: drivers/usb/gadget/g_printer.o(.data+0xc): Section mismatch in
	reference from the variable printer_driver to the function
	.init.text:printer_bind()
	The variable printer_driver references
	the function __init printer_bind()

All callers are fixed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[m.nazarewicz@samsung.com: added dbgp]
Signed-off-by: Michał Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/langwell_udc.c b/drivers/usb/gadget/langwell_udc.c
index ccc9c07..1ef17a6 100644
--- a/drivers/usb/gadget/langwell_udc.c
+++ b/drivers/usb/gadget/langwell_udc.c
@@ -1855,7 +1855,8 @@
  * the driver might get unbound.
  */
 
-int usb_gadget_register_driver(struct usb_gadget_driver *driver)
+int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
+		int (*bind)(struct usb_gadget *))
 {
 	struct langwell_udc	*dev = the_controller;
 	unsigned long		flags;
@@ -1878,7 +1879,7 @@
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	retval = driver->bind(&dev->gadget);
+	retval = bind(&dev->gadget);
 	if (retval) {
 		dev_dbg(&dev->pdev->dev, "bind to driver %s --> %d\n",
 				driver->driver.name, retval);
@@ -1916,7 +1917,7 @@
 	dev_dbg(&dev->pdev->dev, "<--- %s()\n", __func__);
 	return retval;
 }
-EXPORT_SYMBOL(usb_gadget_register_driver);
+EXPORT_SYMBOL(usb_gadget_probe_driver);
 
 
 /* unregister gadget driver */
@@ -1930,7 +1931,7 @@
 
 	dev_dbg(&dev->pdev->dev, "---> %s()\n", __func__);
 
-	if (unlikely(!driver || !driver->bind || !driver->unbind))
+	if (unlikely(!driver || !driver->unbind))
 		return -EINVAL;
 
 	/* exit PHY low power suspend */