[PATCH 0/1] MR1318: ntdll: Write ret_len with the right size in user_mode_callback_return on arm64

[Martin Storsjö (＠mstorsjo)]

This fixes a regression since
4069a8b384c15a90a7af66636ec5650eeb53b391.

This is the same fix as in !1308, but for arm64.