Fix compilation against naemon-core 1.5.1

[eschoeller]

Naemon-core 1.5.1 (released 2026-03-19) adds a check_timeout attribute to the host and service structs, allowing per-object timeout overrides. The new int check_timeout field is inserted between initial_state and check_interval in both struct host and struct service, and the setup_host_variables() and setup_service_variables() function signatures are updated to include it as a parameter.

This breaks merlin compilation against naemon-core 1.5.1 headers:

module/oconfsplit.c:222:3: error: too few arguments to function 'setup_service_variables'
module/oconfsplit.c:197:3: error: too few arguments to function 'setup_host_variables'

This PR adds h->check_timeout and s->check_timeout to the respective function calls in module/oconfsplit.c. These are the only two call sites for these functions in the merlin codebase.

Also fixes a minor whitespace issue in the setup_host_variables call (h-> initial_state -> h->initial_state).

Testing:

• Compiled successfully against naemon-core 1.5.1 and naemon-livestatus 1.5.1 headers on RHEL 8
• Deployed to a 2-node naemon cluster running 1.5.1
• Verified merlin peering, check distribution (~50/50 split), failover (one node down, other takes 100%), and re-peering (checks redistribute within ~60 seconds)
• Livestatus queries working correctly

Note: Our deployment does not use the oconfsplit config splitting functionality — we distribute config via a separate git-based workflow. The fix is straightforward (passing the new struct field to the function call), but we have not been able to functionally test the oconfsplit code path itself.

Refs:

• https://www.naemon.io/news/2026-03-19-release-1.5.1
• https://github.com/naemon/naemon-core/releases/tag/v1.5.1