[PATCH 4/5] d3d8/tests: Use a custom GUID for the private data tests.

[Marvin]

Hi,

While running your changed tests on Windows, 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://newtestbot.winehq.org/JobDetails.pl?Key=5628

Your paranoid android.


=== w8 (32 bit device) ===
device.c:2396: Test failed: Expected foreground window 000401E4, got 00010048.
device.c:3038: Test failed: Expected wndproc 0x40fa10, got 0x40fa10.