[media] media, cx231xx: Fix double free on close

In cx231xx_v4l2_close() there are two calls to
cx231xx_release_resources(dev) followed by kfree(dev). That is a
problem since cx231xx_release_resources() already kfree()'s its
argument, so we end up doing a double free.

Easily resolved by just removing the redundant kfree() calls after the
calls to cx231xx_release_resources().

I also changed the 'dev = NULL' assignments (which are rather
pointless since 'dev' is about to go out of scope), to 'fh->dev = NULL'
since it looks to me that that is what was actually intended.
And I removed the 'dev = NULL' assignment at the end of
cx231xx_release_resources() since it is pointless.

Signed-off-by: Jesper Juhl <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/video/cx231xx/cx231xx-cards.c

···
 	kfree(dev->sliced_cc_mode.alt_max_pkt_size);
 	kfree(dev->ts1_mode.alt_max_pkt_size);
 	kfree(dev);
-	dev = NULL;
 }
 
 /*

drivers/media/video/cx231xx/cx231xx-video.c

···
 			if (dev->state & DEV_DISCONNECTED) {
 				if (atomic_read(&dev->devlist_count) > 0) {
 					cx231xx_release_resources(dev);
-					kfree(dev);
-					dev = NULL;
+					fh->dev = NULL;
 					return 0;
 				}
 				return 0;
···
 		   free the remaining resources */
 		if (dev->state & DEV_DISCONNECTED) {
 			cx231xx_release_resources(dev);
-			kfree(dev);
-			dev = NULL;
+			fh->dev = NULL;
 			return 0;
 		}