usb: gadget: composite: fix bMaxPacketSize for SuperSpeed

For bMaxPacketSize0 we usually take what is specified in ep0->maxpacket.
This is fine in most cases, however on SuperSpeed bMaxPacketSize0
specifies the exponent instead of the actual size in bytes. The only
valid value on SS is 9 which denotes 512 bytes.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/composite.c

@@ -1079,10 +1079,12 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 			cdev->desc.bMaxPacketSize0 =
 				cdev->gadget->ep0->maxpacket;
 			if (gadget_is_superspeed(gadget)) {
-				if (gadget->speed >= USB_SPEED_SUPER)
+				if (gadget->speed >= USB_SPEED_SUPER) {
 					cdev->desc.bcdUSB = cpu_to_le16(0x0300);
-				else
+					cdev->desc.bMaxPacketSize0 = 9;
+				} else {
 					cdev->desc.bcdUSB = cpu_to_le16(0x0210);
+				}
 			}
 
 			value = min(w_length, (u16) sizeof cdev->desc);