libafs: fix error location code in LINUX/osi_export

Fix the missing error location code introduced in commit
40fb2650b783fbafe51aefd3d0af7a6b0536c265
libafs: allocate vattrs in LINUX to reduce stack used

Use location number 104, which is the next in the sequence.

The code in this module is compiled when building the
nfs translator, which is only built under linux when
configure detects it is possible.

Thanks to Andrew Deason for spotting this error.

Change-Id: I00c834bc915fa3be7d5f27467895930e4f62aa76
Reviewed-on: http://gerrit.openafs.org/11351
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: D Brashear <shadow@your-file-system.com>