getgrouplist(3) was reimplemented in terms of getgrent_r(3) in r174547, so
this bug is no longer valid.

MFC after:	3 days


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273717 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f