Fix small mistake in r3980: that `assert` only makes sense for a `shutdown(tid)`.
Fix small mistake in r3980: that `assert` only makes sense for a `shutdown(tid)`.

git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@3981 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac