staging: r8188eu: remove unused dma_transfer_addr

The dma_transfer_addr component in struct xmit_buf is initialised but not
used. Remove it.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20221230180646.91008-14-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_xmit.c

@@ -41,7 +41,6 @@ static int rtw_xmit_resource_alloc(struct adapter *padapter, struct xmit_buf *px
 		return -ENOMEM;
 
 	pxmitbuf->pbuf = (u8 *)ALIGN((size_t)(pxmitbuf->pallocated_buf), XMITBUF_ALIGN_SZ);
-	pxmitbuf->dma_transfer_addr = 0;
 
 	pxmitbuf->pxmit_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!pxmitbuf->pxmit_urb) {

drivers/staging/r8188eu/include/rtw_xmit.h

@@ -202,7 +202,6 @@ struct xmit_buf {
 	struct submit_ctx *sctx;
 	u32	ff_hwaddr;
 	struct urb *pxmit_urb;
-	dma_addr_t dma_transfer_addr;	/* (in) dma addr for transfer_buffer */
 	int last[8];
 };