Coding error in recipes/lock/src/c/src/zoo_lock.c

In fuction child_floor(), strcmp() is used to compare the whole string.
But there exists conditions a sorted_data looks like ("x-000-00", "x-222-01", "x-111-02"), and now "x-222-01" is calling child_floor() to get a predecessor for watching, so the current logic will return "x-111-02" instead of the correct "x-000-00".
Use a strcmp() == 0 and a break statement should solve this problem.