WINMM/tests: failures in mixer.c

[Saulius Krasuckas]

| $ wine dlls/winmm/tests/winmm_test.exe.so mixer
| fixme:opengl:X11DRV_setup_opengl_visual Failed to find a suitable visual
| mixer.c:962:--- Testing ASCII functions ---
| mixer.c:965:found 1 Mixer devices
| mixer.c:374:  0: "mad16 WSS (82C930)" 1.0 (170:85)
| mixer.c:240: Test failed: Couldn't change value from 153354 to 152698, returned 153354
| mixer.c:988:--- Testing WCHAR functions ---
| mixer.c:991:found 1 Mixer devices
| mixer.c:756:  0: "mad16 WSS (82C930)" 1.0 (170:85)
| mixer.c:617: Test failed: Couldn't change value from 153354 to 152698, returned 153354
| mixer: 144 tests executed, 0 marked as todo, 2 failures.

Any ideas on what could be wrong?