usb: dwc3: gadget: improve ep_queue's error reporting

We shouldn't return -EBUSY, that's used only internally
when the core still has transfers in flight on a given
endpoint.

Also, combine the error reporting so that we don't have
to duplicate it.

Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -1080,10 +1080,7 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 	if (!usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
 			!(dep->flags & DWC3_EP_BUSY)) {
 		ret = __dwc3_gadget_kick_transfer(dep, 0, true);
-		if (ret && ret != -EBUSY)
-			dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
-					dep->name);
-		return ret;
+		goto out;
 	}
 
 	/*
@@ -1113,14 +1110,10 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 		}
 
 		ret = __dwc3_gadget_kick_transfer(dep, 0, true);
-		if (ret && ret != -EBUSY)
-			dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
-					dep->name);
-
 		if (!ret)
 			dep->flags &= ~DWC3_EP_PENDING_REQUEST;
 
-		return ret;
+		goto out;
 	}
 
 	/*
@@ -1134,10 +1127,7 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 		WARN_ON_ONCE(!dep->resource_index);
 		ret = __dwc3_gadget_kick_transfer(dep, dep->resource_index,
 				false);
-		if (ret && ret != -EBUSY)
-			dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
-					dep->name);
-		return ret;
+		goto out;
 	}
 
 	/*
@@ -1145,14 +1135,17 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 	 * right away, otherwise host will not know we have streams to be
 	 * handled.
 	 */
-	if (dep->stream_capable) {
+	if (dep->stream_capable)
 		ret = __dwc3_gadget_kick_transfer(dep, 0, true);
-		if (ret && ret != -EBUSY)
-			dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
-					dep->name);
-	}
 
-	return 0;
+out:
+	if (ret && ret != -EBUSY)
+		dev_dbg(dwc->dev, "%s: failed to kick transfers\n",
+				dep->name);
+	if (ret == -EBUSY)
+		ret = 0;
+
+	return ret;
 }
 
 static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,