nvme: Note in which AioContext some functions run

nvme: Note in which AioContext some functions run

Sprinkle comments throughout block/nvme.c noting for some functions
(where it may not be obvious) that they require a certain AioContext, or
in which AioContext they do happen to run (for callbacks, BHs, event
notifiers).

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20251110154854.151484-10-hreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>