Fix inner attribute syntax from `#[foo];` to `#![foo]`

From the 0.10 changelog:
 * The inner attribute syntax has changed from `#[foo];` to `#![foo]`.

I've run the tests, but I've got results I do not understand:
https://tim.siosm.fr/downloads/rust_tests_master.log (run on f819c21)
https://tim.siosm.fr/downloads/rust_tests_patched.log (run on f819c21 + patch; I've made a rebase since but did not rerun the checks)