thermal: core: Replace sprintf() in thermal_bind_cdev_to_trip()

thermal: core: Replace sprintf() in thermal_bind_cdev_to_trip()

Replace unbounded sprintf() with the safer snprintf(). While the
current code works correctly, snprintf() is safer and follows secure
coding best practices.

No functional changes.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Subject tweaks ]
Link: https://patch.msgid.link/20260223073245.321298-2-thorsten.blum@linux.dev
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>