message: Always set memptr in posix_memalign()
diff: @@ -647,13 +647,14 @@ pub unsafe extern "C" fn posix_memalign(
  if alignment % VOID_PTR_SIZE == 0 && alignment.is_power_of_two() {
  let ptr = platform::alloc_align(size, alignment);
  - if !ptr.is_null() {
  *memptr = ptr;
  - 0
  - } else {
  + if ptr.is_null() {
  ENOMEM
  + } else {
  + 0
  }
  } else {
  + *memptr = ptr::null_mut();
  EINVAL
  }
  }
  