ste_dma40: Delete an unnecessary variable initialisation in d40_probe()

The variable "res" will eventually be set to a resource pointer from
a call of the d40_hw_detect_init(() function.
Thus let us omit the explicit initialisation at the beginning.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ste_dma40.c

@@ -3544,7 +3544,7 @@ static int __init d40_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	int ret = -ENOENT;
 	struct d40_base *base;
-	struct resource *res = NULL;
+	struct resource *res;
 	int num_reserved_chans;
 	u32 val;