Allocate correct size (portably) in drivers/usb/gadget/f_midi.c::f_midi_bind()

As the coverity checker puts it:

"Passing argument "sizeof (midi_function) /*8*/" to function "kcalloc"
and then casting the return value to "struct usb_descriptor_header **"
is suspicious. ... In this particular case sizeof(struct
usb_descriptor_header **) happens to be equal to sizeof(struct
usb_descriptor_header *), but this is not a portable assumption."

I believe we really do intend to use 'sizeof(*midi_function)' here, so
this patch makes that change.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/f_midi.c

@@ -780,7 +780,7 @@ f_midi_bind(struct usb_configuration *c, struct usb_function *f)
 	midi->out_ep->driver_data = cdev;	/* claim */
 
 	/* allocate temporary function list */
-	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(midi_function),
+	midi_function = kcalloc((MAX_PORTS * 4) + 9, sizeof(*midi_function),
 				GFP_KERNEL);
 	if (!midi_function) {
 		status = -ENOMEM;