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/gmidi.c b/drivers/usb/gadget/gmidi.c
index b7bf880..0ab7e14 100644
--- a/drivers/usb/gadget/gmidi.c
+++ b/drivers/usb/gadget/gmidi.c
@@ -1292,7 +1292,6 @@
 static struct usb_gadget_driver gmidi_driver = {
 	.speed		= USB_SPEED_FULL,
 	.function	= (char *)longname,
-	.bind		= gmidi_bind,
 	.unbind		= gmidi_unbind,
 
 	.setup		= gmidi_setup,
@@ -1309,7 +1308,7 @@
 
 static int __init gmidi_init(void)
 {
-	return usb_gadget_register_driver(&gmidi_driver);
+	return usb_gadget_probe_driver(&gmidi_driver, gmidi_bind);
 }
 module_init(gmidi_init);