[PATCH 2/2] user32/combo: Fix listbox size when combobox is very small

[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=48543

Your paranoid android.


=== debian9 (32 bit Japanese:Japan report) ===

user32:
combo.c:767: Test succeeded inside todo block: Test 3, expected list height to be 0, got 0
combo.c:767: Test succeeded inside todo block: Test 12, expected list height to be 0, got 0
combo.c:767: Test succeeded inside todo block: Test 17, expected list height to be 54, got 54

=== debian9 (32 bit Chinese:China report) ===

user32:
msg.c:14491: Test failed: bad time b5e4e9f