gssapi_get_default_name(): use gss_release_buffer(), rathen than free() directly.
gssapi_get_default_name(): use gss_release_buffer(), rathen than
free() directly.

gssapi_init(): make sure to release the "cred" buffer after we're
done using it.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame