sysctl_lock
sysctl_lock(new != NULL);
sysctl_lock(ls.newval != NULL);
sysctl_lock(NETBSD32PTR64(ls32.newval) != NULL);
sysctl_lock(newp != NULL);
sysctl_lock(true);
sysctl_lock(true);
sysctl_lock(newp != NULL);
sysctl_lock(SCARG(uap, newv) != NULL);
sysctl_lock(false);
void sysctl_lock(bool);