V4L/DVB (11995): zr364xx.c: vfree does its own NULL check

vfree() does it's own NULL checking, no need for explicit check before
calling it.
Signed-off-by: Figo.zhang <figo1802@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/zr364xx.c

@@ -882,9 +882,11 @@ static void zr364xx_disconnect(struct usb_interface *intf)
 		video_unregister_device(cam->vdev);
 	cam->vdev = NULL;
 	kfree(cam->buffer);
-	if (cam->framebuf)
+	cam->buffer = NULL;
 	vfree(cam->framebuf);
+	cam->framebuf = NULL;
 	kfree(cam);
+	cam = NULL;
 }