staging: r8188eu: Fix return type of rtw_xmit_entry

The ndo_start_xmit field in net_device_ops is expected to be of type
netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb, struct net_device *dev).

The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition.

The return type of rtw_xmit_entry should be changed from int to
netdev_tx_t.

Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@lists.linux.dev
Reported-by: Dan Carpenter <error27@gmail.com>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Link: https://lore.kernel.org/r/20220914211606.423959-1-nhuck@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_xmit.c

@@ -2309,7 +2309,7 @@ static int rtw_mlcst2unicst(struct adapter *padapter, struct sk_buff *skb)
 	return true;
 }
 
-int rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
+netdev_tx_t rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
 {
 	struct adapter *padapter = (struct adapter *)rtw_netdev_priv(pnetdev);
 	struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
@@ -2343,5 +2343,5 @@ int rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev)
 	dev_kfree_skb_any(pkt);
 
 exit:
-	return 0;
+	return NETDEV_TX_OK;
 }

drivers/staging/r8188eu/include/rtw_xmit.h

@@ -368,6 +368,6 @@ int rtw_ack_tx_wait(struct xmit_priv *pxmitpriv, u32 timeout_ms);
 void rtw_ack_tx_done(struct xmit_priv *pxmitpriv, int status);
 
 void rtw_xmit_complete(struct adapter *padapter, struct xmit_frame *pxframe);
-int rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev);
+netdev_tx_t rtw_xmit_entry(struct sk_buff *pkt, struct net_device *pnetdev);
 
 #endif	/* _RTL871X_XMIT_H_ */