dmaengine: dw: drop useless LIST_HEAD

Drop LIST_HEAD where the variable it declares is never used.

Commit ab703f818a ("dmaengine: dw: lazy allocation of dma
descriptors") removed the uses, but not the declaration.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
@@
- LIST_HEAD(x);
  ... when != x
// </smpl>

Fixes: ab703f818a ("dmaengine: dw: lazy allocation of dma descriptors")
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dw/core.c

@@ -1150,7 +1150,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
 	struct dw_dma		*dw = to_dw_dma(chan->device);
 	unsigned long		flags;
-	LIST_HEAD(list);
 
 	dev_dbg(chan2dev(chan), "%s: descs allocated=%u\n", __func__,
 			dwc->descs_allocated);