user32/tests: Add space for the mask data to prevent failures on Win 8 and 10.

[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://testbot.winehq.org/JobDetails.pl?Key=25848

Your paranoid android.


=== w864 (32 bit cursoricon) ===
cursoricon.c:2625: Test failed: LoadImage() failed with 0.
cursoricon.c:2625: Test failed: LoadImage() failed with 0.

=== w1064 (32 bit cursoricon) ===
cursoricon.c:2625: Test failed: LoadImage() failed with 0.
cursoricon.c:2625: Test failed: LoadImage() failed with 0.

=== w1064 (64 bit cursoricon) ===
cursoricon.c:2625: Test failed: LoadImage() failed with 0.
cursoricon.c:2625: Test failed: LoadImage() failed with 0.