usb: dwc3: rename res_trans_idx to resource_index

resource_index is more human readable. No
functional changes.

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 90eb1ba..9a8f26c 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -113,7 +113,7 @@
 	}
 
 	dep->flags |= DWC3_EP_BUSY;
-	dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
+	dep->resource_index = dwc3_gadget_ep_get_transfer_index(dwc,
 			dep->number);
 
 	dwc->ep0_next_event = DWC3_EP0_COMPLETE;
@@ -757,7 +757,7 @@
 	struct dwc3_ep		*dep = dwc->eps[event->endpoint_number];
 
 	dep->flags &= ~DWC3_EP_BUSY;
-	dep->res_trans_idx = 0;
+	dep->resource_index = 0;
 	dwc->setup_packet_pending = false;
 
 	switch (dwc->ep0state) {