Destroy a Mutex
Use mutex_destroy(3C) to destroy any state that is associated with the mutex
pointed to by mp . The space for storing the mutex
is not freed. For POSIX threads, see pthread_mutex_destroy Syntax.
int mutex_destroy (mutex_t *mp);
mutex_destroy Return Values
mutex_destroy() returns 0
if successful. When the following condition is detected, mutex_destroy() fails
and returns the corresponding value.
mp points to
an illegal address.