atomic_sync: Use the correct struct timespec on NetBSD for futex.

This is a minimum fix for the NetBSD futex syscall, but perhaps it
would be better to just use struct timespec on all systems and have a
special case for Linux's pre-64-bit-time_t syscall.

fix #49

bee/thread/atomic_sync.cpp

@@ -49,7 +49,11 @@ static void futex_wait(const int* ptr, int val, const FutexTimespec* timeout) {
 #    if defined(__linux__)
     ::syscall(SYS_futex, ptr, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, timeout, 0, 0);
 #    elif defined(__NetBSD__)
-    ::syscall(SYS___futex, ptr, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, timeout, 0, 0, 0);
+    struct timespec ts = {
+        .tv_sec = timeout.tv_sec,
+        .tv_nsec = timeout.tv,
+    };
+    ::syscall(SYS___futex, ptr, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, &ts, 0, 0, 0);
 #    elif defined(__OpenBSD__)
     static_assert(sizeof(FutexTimespec) == sizeof(timespec));
     ::futex((uint32_t*)const_cast<int*>(ptr), FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, (const timespec*)timeout, 0);