Asserting that specific log entries were printed isn't all that
useful, we should really be focusing on the expected messages (or,
when a monitor udpate fails, the lack thereof). In the next commit
one of these log checks would otherwise break due to the particular
time a monitor update fails changing, but I also plan on reworking
the montior update flows substantially soon, breaking lots of them.

When we process a `channel_reestablish` message we free the HTLC
update holding cell as things may have changed while we were
disconnected. However, some time ago, to handle freeing from the
holding cell when a monitor update completes, we added a holding
cell freeing check in `get_and_clear_pending_msg_events`. This
leaves the in-`channel_reestablish` holding cell clear redundant,
as doing it immediately or is `get_and_clear_pending_msg_events` is
not a user-visible difference.

Thus, we remove the redundant code here, substantially simplifying
`handle_chan_restoration_locked` while we're at it.

There is no reason anymore for `handle_chan_restoration_locked` to
be a macro, and our long-term desire is to move away from macros as
they substantially bloat our compilation time (and binary size).
Thus, we simply remove `handle_chan_restoration_locked` here and
turn it into a function.

Now that `handle_channel_resumption` can't fail, the error handling
in `post_handle_chan_restoration` is now dead code. Removing it
makes `post_handle_chan_restoration` only a single block, so here
we simply remove the macro and inline the single block into the two
places the macro was used.