selftest: Use scalar variable for new daemon_ctx hashmap

selftest: Use scalar variable for new daemon_ctx hashmap

The selftest code typically stores hashmaps as scalar variables (i.e.
it only ever uses references to hashmaps). So much so that using a regular
hashmap (and passing it by reference via \%daemon_ctx) looks out of
place.

Using the hashmap directly made more sense when it was only being used
locally, but now the hashmap is being passed by reference into a function
anyway, so storing it as a scalar doesn't make much difference.

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>