V4L/DVB (4288): Clean out a zillion sparse warnings in pvrusb2

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/pvrusb2/pvrusb2-video-v4l.c b/drivers/media/video/pvrusb2/pvrusb2-video-v4l.c
index e4ec7f2..05f2cdd 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-video-v4l.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-video-v4l.c
@@ -126,8 +126,8 @@
 
 static void decoder_detach(struct pvr2_v4l_decoder *ctxt)
 {
-	ctxt->client->handler = 0;
-	ctxt->hdw->decoder_ctrl = 0;
+	ctxt->client->handler = NULL;
+	ctxt->hdw->decoder_ctrl = NULL;
 	kfree(ctxt);
 }