Correctly encode doc attribute metadata

[GuillaumeGomez]

Follow-up of #149645.

The change I made was slightly wrong. Originally the check was:

        if let Some(item_list) = attr.meta_item_list() {
            for item in item_list {
                if !item.has_name(sym::inline) {

So we were checking that there was no doc(inline) attribute. This PR should fix it.

r? @lqd

[rustbot]

Some changes occurred in compiler/rustc_hir/src/attrs

cc @jdonszelmann

[fmease]

Is this regression user observable? If so, it would be nice to add a test exercising it.

[GuillaumeGomez]

Would be nice indeed. Gonna try to trigger a bug with it.