fbdev: auo_k190x: Use zeroing memory allocator instead of allocator/memset

Use vzalloc for allocating zeroed memory and remove unnecessary
memset function.

Done using Coccinelle.
Generated-by scripts/coccinelle/api/alloc/kzalloc-simple.cocci.
0-day tested with no failures.
Suggested-by: NLuis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: NHimanshu Jha <himanshujha199640@gmail.com>
[b.zolnierkie: fixed minor issues in the patch description]
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/auo_k190x.c

@@ -1056,13 +1056,12 @@ int auok190x_common_probe(struct platform_device *pdev,
 	/* videomemory handling */
 
 	videomemorysize = roundup((panel->w * panel->h) * 2, PAGE_SIZE);
-	videomemory = vmalloc(videomemorysize);
+	videomemory = vzalloc(videomemorysize);
 	if (!videomemory) {
 		ret = -ENOMEM;
 		goto err_irq;
 	}
 
-	memset(videomemory, 0, videomemorysize);
 	info->screen_base = (char *)videomemory;
 	info->fix.smem_len = videomemorysize;