media: vivid: use vfree() instead of kfree() for dev->bitmap_cap

syzkaller reported crashes on kfree() called from
vivid_vid_cap_s_selection(). This looks like a simple typo, as
dev->bitmap_cap is allocated with vzalloc() throughout the file.

Fixes: ef834f78 ("[media] vivid: add the video capture and output
parts")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Syzbot <syzbot+6c0effb5877f6b0344e2@syzkaller.appspotmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/vivid/vivid-vid-cap.c

@@ -1007,7 +1007,7 @@ int vivid_vid_cap_s_selection(struct file *file, void *fh, struct v4l2_selection
 		v4l2_rect_map_inside(&s->r, &dev->fmt_cap_rect);
 		if (dev->bitmap_cap && (compose->width != s->r.width ||
 					compose->height != s->r.height)) {
-			kfree(dev->bitmap_cap);
+			vfree(dev->bitmap_cap);
 			dev->bitmap_cap = NULL;
 		}
 		*compose = s->r;