dmaengine: stm32-dma: remove unused ‘src_addr’

In stm32_dma_set_xfer_param(), variable ‘src_addr’ is initialized but never used, which
leads to warning with W=1

drivers/dma/stm32-dma.c: In function ‘stm32_dma_set_xfer_param’:
drivers/dma/stm32-dma.c:577:13: warning: variable ‘src_addr’ set but not used [-Wunused-but-set-variable]
  dma_addr_t src_addr, dst_addr;

So remove it.
Reviewed-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/stm32-dma.c

@@ -573,14 +573,12 @@ static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
 	int src_bus_width, dst_bus_width;
 	int src_burst_size, dst_burst_size;
 	u32 src_maxburst, dst_maxburst;
-	dma_addr_t src_addr;
 	u32 dma_scr = 0;
 
 	src_addr_width = chan->dma_sconfig.src_addr_width;
 	dst_addr_width = chan->dma_sconfig.dst_addr_width;
 	src_maxburst = chan->dma_sconfig.src_maxburst;
 	dst_maxburst = chan->dma_sconfig.dst_maxburst;
-	src_addr = chan->dma_sconfig.src_addr;
 
 	switch (direction) {
 	case DMA_MEM_TO_DEV: