If the SendMessageTimeout call takes a long time, we can get other
messages which also set the observed wparam value. Apparently,
this is especially likely on Windows 7.

This also removes the (wParam == 0xbaadbeef) check which may have
been intended to serve the same goal but doesn't work because the
observed wParam value is still assigned.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54194