staging/comedi: fix syntax error

I don't know how gcc interprets this, but it wouldn't surprise me if it
choose something different than start-of-comment

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/comedi/drivers/addi-data/hwdrv_APCI1710.c

@@ -1,4 +1,4 @@
-//**
+/**
 @verbatim
 
 Copyright (C) 2004,2005  ADDI-DATA GmbH for the source code of this module.