FBSD: typo fix

FBSD: typo fix

Gerrit/5572 added conditionals on __FreeBSD_version >= 900044, which
is (approximately) when a bunch of kernel API renames happened.
(There has since been a dedicated version bump to 900045 a month
or two post-facto, but 900044 should be fine for now.)
However, 900044 is not 90004.

Change-Id: I566186a7b53fd3b605a0f531e241eaf54a96bba3
Reviewed-on: http://gerrit.openafs.org/5657
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>