re: curlwp usage in some devices

[matthew green <mrg%eterna.com.au@localhost>]

   Please take a look at the attached diff. It removes curlwp->l_cred usage
   in favor of kauth_cred_get(). I didn't commit as I'm not sure whether
   removing the "curlwp == NULL" checks is okay or not -- can curlwp be
   NULL?


i didn't look closely at the diff so please don't take this as a
review of the change itself.

curlwp will never be NULL in a device driver in netbsd 5.0 or later.
it is set to non-NULL very early during boot, and never should
become NULL again.


.mrg.