Staging: comedi: drivers: fix coding style issues in das16.c

This is a patch to the das16.c file that fixes up the following issues
found by the checkpatch.pl tool.

WARNING: line over 80 characters x 23
ERROR: spaces required around that '?' (ctx:VxV) x 2
ERROR: spaces required around that ':' (ctx:VxV) x 2
WARNING: printk() should include KERN_ facility level x 17
WARNING: braces {} are not necessary for single statement blocks x 8
Signed-off-by: Gustavo Silva <silvagustavo@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>