V4L/DVB (3277): Fix incorrect filename reference in top comments

- Fix incorrect filename reference in top comments
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>

drivers/media/video/em28xx/em28xx.h

 /*
-   em28xx-cards.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
+   em28xx.h - driver for Empia EM2800/EM2820/2840 USB video capture devices
 
    Copyright (C) 2005 Markus Rechberger <mrechberger@gmail.com>
 		      Ludovico Cavedon <cavedon@sssup.it>