[PATCH] ntdll: Fix unwinding from leaf function on x86_64.

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=49463

Your paranoid android.


=== debian9b (64 bit WoW report) ===

ntdll:
env.c:498: Test failed: wrong end ptr 0x1238c/0x12390