Fix `mut_mutex_lock` when reference not ultimately mutable

When there is are multiple references where one of the references
isn't mutable then this results in a false-positive for
`mut_mutex_lock` as it only checks the mutability of the first
reference level.

Fix this by using `peel_mid_ty_refs_is_mutable` which correctly
determines whether the reference is ultimately mutable and thus
whether `Mutex::get_lock()` can actually be used.

Fixes #9854

0 files changed, 0 insertions, 0 deletions