Remove unnecessary assignment

This gets updated at the end of a collection anyway so the additional
check doesn't add anything except overcomplicate things.

reclaim.c

@@ -889,7 +889,6 @@ static void* init_finalize_thread(void *arg)
 {
   while(1) {
     pthread_mutex_lock(&flzr_mtx);
-    flzr_can_work = GC_should_invoke_finalizers();
     while (flzr_can_work == 0) {
       pthread_cond_wait(&flzr_t_has_work, &flzr_mtx);
     }