Staging: comedi: clean up sparse issues in proc.c

The whole file should be converted to use seqfile, if it's even
still needed.  Or move to debugfs.

Anyway, I fixed up the minor issues here.

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