Staging: comedi: fix bracing coding style issue in ni_65xx.c

This is a patch to the ni_65xx.c file that fixes up a brace
warning found by the checkpatch.pl tool

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