drivers/rapidio/devices/tsi721_dma.c: delete an unnecessary variable initialisation in tsi721_alloc_chan_resources()

The local variable "desc" will eventually be set to an appropriate pointer
a bit later. Thus omit the explicit initialisation at the beginning.

Link: http://lkml.kernel.org/r/728d8e20-4ae9-d661-d932-2d99ce67e71f@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rapidio/devices/tsi721_dma.c

@@ -735,7 +735,7 @@ static dma_cookie_t tsi721_tx_submit(struct dma_async_tx_descriptor *txd)
 static int tsi721_alloc_chan_resources(struct dma_chan *dchan)
 {
 	struct tsi721_bdma_chan *bdma_chan = to_tsi721_chan(dchan);
-	struct tsi721_tx_desc *desc = NULL;
+	struct tsi721_tx_desc *desc;
 	int i;
 
 	tsi_debug(DMA, &dchan->dev->device, "DMAC%d", bdma_chan->id);