[WINMM][SNDVol32] Closing while ll-driver open

reactos-bootcd-0.4.16-dev-127-g478a903-x86-gcc-lin-dbg

• Open SndVol32
• Open Properties => This is the critical step

• Close properties
• Close SndVol32
• Logs :  Closing while ll-driver open (one occurence per opening of Properties page)
• Code of interest : MMDRV_Exit in dll/win32/winmm/lolvldrv.c in https://git.reactos.org/?p=reactos.git;a=blob;f=dll/win32/winmm/lolvldrv.c;hb=30952992e1a13b8f0c0bb4cabfaffe4ef3451522#l620