staging: r8188eu: remove unnecessary vaiable in rtw_recv

Return _SUCCESS directly instead of storing it in a variable.
This can prevent cocci warning as follows:

  Unneeded variable: "ret". Return "_SUCCESS" on line 1516

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Kang Minchul <tegongkang@gmail.com>
Link: https://lore.kernel.org/r/20221025170621.271903-3-tegongkang@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_recv.c

@@ -1415,7 +1415,6 @@ static int amsdu_to_msdu(struct adapter *padapter, struct recv_frame *prframe)
 
 	struct recv_priv *precvpriv = &padapter->recvpriv;
 	struct __queue *pfree_recv_queue = &precvpriv->free_recv_queue;
-	int	ret = _SUCCESS;
 
 	nr_subframes = 0;
 
@@ -1513,7 +1512,7 @@ static int amsdu_to_msdu(struct adapter *padapter, struct recv_frame *prframe)
 	prframe->len = 0;
 	rtw_free_recvframe(prframe, pfree_recv_queue);/* free this recv_frame */
 
-	return ret;
+	return _SUCCESS;
 }
 
 static bool check_indicate_seq(struct recv_reorder_ctrl *preorder_ctrl, u16 seq_num)