media: atomisp: Fix use after free in atomisp_alloc_css_stat_bufs()

The "s3a_buf" is freed along with all the other items on the
"asd->s3a_stats" list.  It leads to a double free and a use after free.

Link: https://lore.kernel.org/linux-media/X9dSO3RGf7r0pq2k@mwanda
Fixes: ad85094b ("Revert "media: staging: atomisp: Remove driver"")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/atomisp/pci/atomisp_ioctl.c

@@ -948,10 +948,8 @@ int atomisp_alloc_css_stat_bufs(struct atomisp_sub_device *asd,
 		dev_dbg(isp->dev, "allocating %d dis buffers\n", count);
 		while (count--) {
 			dis_buf = kzalloc(sizeof(struct atomisp_dis_buf), GFP_KERNEL);
-			if (!dis_buf) {
-				kfree(s3a_buf);
+			if (!dis_buf)
 				goto error;
-			}
 			if (atomisp_css_allocate_stat_buffers(
 				asd, stream_id, NULL, dis_buf, NULL)) {
 				kfree(dis_buf);