usb: gadget: f_hid: use free_ep_req()

We should always use free_ep_req() when allocating requests with
alloc_ep_req().

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c
index fa807ce..aa1c199 100644
--- a/drivers/usb/gadget/function/f_hid.c
+++ b/drivers/usb/gadget/function/f_hid.c
@@ -677,11 +677,8 @@
 	usb_free_all_descriptors(f);
 fail:
 	ERROR(f->config->cdev, "hidg_bind FAILED\n");
-	if (hidg->req != NULL) {
-		kfree(hidg->req->buf);
-		if (hidg->in_ep != NULL)
-			usb_ep_free_request(hidg->in_ep, hidg->req);
-	}
+	if (hidg->req != NULL)
+		free_ep_req(hidg->in_ep, hidg->req);
 
 	return status;
 }
@@ -920,8 +917,7 @@
 
 	/* disable/free request and end point */
 	usb_ep_disable(hidg->in_ep);
-	kfree(hidg->req->buf);
-	usb_ep_free_request(hidg->in_ep, hidg->req);
+	free_ep_req(hidg->in_ep, hidg->req);
 
 	usb_free_all_descriptors(f);
 }