When ram_block_discard_require() fails, errno is passed to error_setg_errno().
It's a stale value or 0 which is unrelated to ram_block_discard_require().
As ram_block_discard_require() already returns -EBUSY in failure case,
use it as errno for error_setg_errno().
Fixes: 852f0048f3 ("make guest_memfd require uncoordinated discard")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-ID: <20240716064213.290696-1-zhenzhong.duan@intel.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
644a52778a