drm/etnaviv: remove unneeded variable initialization

There is no need to initialize variable 'err' with 0 because it will
be properly assigned later on.
Signed-off-by: NFabio Estevam <festevam@gmail.com>

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1652,7 +1652,7 @@ static int etnaviv_gpu_platform_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct etnaviv_gpu *gpu;
-	int err = 0;
+	int err;
 
 	gpu = devm_kzalloc(dev, sizeof(*gpu), GFP_KERNEL);
 	if (!gpu)