Staging: comedi: fix checkpatch.pl errors in comedi_fops.c

There are still some >80 character lines in there, but
this catches the majority of the issues.

Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Cc: David Schleef <ds@schleef.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>