usb: gadget: f_hid: use alloc_ep_req()

Use gadget's framework allocation function instead of directly calling
usb_ep_alloc_request().
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/f_hid.c

@@ -617,14 +617,10 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f)
 
 	/* preallocate request and buffer */
 	status = -ENOMEM;
-	hidg->req = usb_ep_alloc_request(hidg->in_ep, GFP_KERNEL);
+	hidg->req = alloc_ep_req(hidg->in_ep, hidg->report_length);
 	if (!hidg->req)
 		goto fail;
 
-	hidg->req->buf = kmalloc(hidg->report_length, GFP_KERNEL);
-	if (!hidg->req->buf)
-		goto fail;
-
 	/* set descriptor dynamic values */
 	hidg_interface_desc.bInterfaceSubClass = hidg->bInterfaceSubClass;
 	hidg_interface_desc.bInterfaceProtocol = hidg->bInterfaceProtocol;