- postinst_restore: switch from BIN_PATH start to INIT_PATH start so
the test-injected init script is exercised (the test sets TACHYON_INIT
to a fake init that writes to a log; BIN_PATH was never the fake init)
- postinst_restore: guard process-killing with !PACKAGE_TEST_MODE,
consistent with prerm_cleanup — the start call itself is always made
- flock deadlock risk is gone: prerm_cleanup now kills all waiters
before removing the routing table entry, so INIT_PATH start is safe