thermal: core: Drop redundant thermal instance checks

thermal: core: Drop redundant thermal instance checks

Because the trip and cdev pointers are sufficient to identify a thermal
instance holding them unambiguously, drop the additional thermal zone
checks from two loops walking the list of thermal instances in a
thermal zone.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://patch.msgid.link/10527734.nUPlyArG6x@rjwysocki.net