4829 sema_init(3C) botches the arguments in an example

*** 104,114 ****
  .sp
  .in +2
  .nf
  sema_t sp;
  int count  =  1;
! sema_init(&sp, count, NULL, NULL);
  .fi
  .in -2
  
  .sp
  .LP
--- 104,114 ----
  .sp
  .in +2
  .nf
  sema_t sp;
  int count  =  1;
! sema_init(&sp, count, 0, NULL);
  .fi
  .in -2
  
  .sp
  .LP