Staging: comedi: fix bracing coding style and 80 character issues in ni_660x.c

This is a patch to the ni_660x.c file that fixes up the brace and 80
character issues found by the checkpatch tool

Signed-off-by: Graham M Howe <gmhowe@btopenworld.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>