fix: use VaList::next_arg for variadic sem_open

src/header/semaphore/mod.rs

@@ -158,7 +158,10 @@ pub unsafe extern "C" fn sem_open(
         return ptr as *mut NamedSemaphore as *mut sem_t;
     }
     let (mode, value): (mode_t, c_uint) = if create {
-        (unsafe { __valist.arg::<mode_t>() }, unsafe { __valist.arg::<c_uint>() })
+        (
+            unsafe { __valist.next_arg::<mode_t>() }.unwrap_or(0),
+            unsafe { __valist.next_arg::<c_uint>() }.unwrap_or(0),
+        )
     } else {
         (0, 0)
     };