usb: dwc3: remove unused @lock member of dwc3_ep struct

The member @lock of dwc3_ep struct is only initialized,
and not used elsewhere, so remove it.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.h

@@ -649,7 +649,6 @@ struct dwc3_event_buffer {
  * @cancelled_list: list of cancelled requests for this endpoint
  * @pending_list: list of pending requests for this endpoint
  * @started_list: list of started requests on this endpoint
- * @lock: spinlock for endpoint request queue traversal
  * @regs: pointer to first endpoint register
  * @trb_pool: array of transaction buffers
  * @trb_pool_dma: dma address of @trb_pool
@@ -677,7 +676,6 @@ struct dwc3_ep {
 	struct list_head	pending_list;
 	struct list_head	started_list;
 
-	spinlock_t		lock;
 	void __iomem		*regs;
 
 	struct dwc3_trb		*trb_pool;

drivers/usb/dwc3/gadget.c

@@ -2271,8 +2271,6 @@ static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
 		dep->endpoint.comp_desc = NULL;
 	}
 
-	spin_lock_init(&dep->lock);
-
 	if (num == 0)
 		ret = dwc3_gadget_init_control_endpoint(dep);
 	else if (direction)