If a name token contains trailing garbage, error out from
krb5_gss_import_name() instead of crashing the process with an
assertion failure.
Commit message details obtained from upstream commit.
Obtained from: upstream commit 07818f1fd
Reported by: Aisle Research (Ze Sheng, Dmitrijs Trizna,
Luigino Camastra, Guido Vranken) to krb5-bugs
MFC after: 3 days
Cy Schubert
fce16f60de