usb:gadget:f_thor: cosmetic: Remove debug memset

Apparently debug memset (with a 0x55 value) has been overlooked in the
f_thor code.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Cc: Marek Vasut <marex@denx.de>

drivers/usb/gadget/f_thor.c

@@ -623,8 +623,6 @@ static struct usb_request *thor_start_ep(struct usb_ep *ep)
 	memset(req->buf, 0, req->length);
 	req->complete = thor_rx_tx_complete;
 
-	memset(req->buf, 0x55, req->length);
-
 	return req;
 }