[PATCH] usb: cleanup with list_first_entry_or_null()

[Masahiro Yamada]

The combo of list_empty() check and return list_first_entry()
can be replaced with list_first_entry_or_null().

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

 drivers/usb/dwc2/gadget.c        | 6 ++----
 drivers/usb/dwc3/gadget.h        | 5 +----
 drivers/usb/renesas_usbhs/fifo.c | 5 +----
 3 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index af46adf..28a250a 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -1098,10 +1098,8 @@ static int dwc2_hsotg_ep_sethalt(struct usb_ep *ep, int value, bool now);
  */
 static struct dwc2_hsotg_req *get_ep_head(struct dwc2_hsotg_ep *hs_ep)
 {
-	if (list_empty(&hs_ep->queue))
-		return NULL;
-
-	return list_first_entry(&hs_ep->queue, struct dwc2_hsotg_req, queue);
+	return list_first_entry_or_null(&hs_ep->queue, struct dwc2_hsotg_req,
+					queue);
 }
 
 /**
diff --git a/drivers/usb/dwc3/gadget.h b/drivers/usb/dwc3/gadget.h
index e4a1d97..3129bcf 100644
--- a/drivers/usb/dwc3/gadget.h
+++ b/drivers/usb/dwc3/gadget.h
@@ -62,10 +62,7 @@ struct dwc3;
 
 static inline struct dwc3_request *next_request(struct list_head *list)
 {
-	if (list_empty(list))
-		return NULL;
-
-	return list_first_entry(list, struct dwc3_request, list);
+	return list_first_entry_or_null(list, struct dwc3_request, list);
 }
 
 static inline void dwc3_gadget_move_started_request(struct dwc3_request *req)
diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 857e783..d1af831 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -100,10 +100,7 @@ static void __usbhsf_pkt_del(struct usbhs_pkt *pkt)
 
 static struct usbhs_pkt *__usbhsf_pkt_get(struct usbhs_pipe *pipe)
 {
-	if (list_empty(&pipe->list))
-		return NULL;
-
-	return list_first_entry(&pipe->list, struct usbhs_pkt, node);
+	return list_first_entry_or_null(&pipe->list, struct usbhs_pkt, node);
 }
 
 static void usbhsf_fifo_clear(struct usbhs_pipe *pipe,
-- 
1.9.1