winmm/tests: Don't use 0x55 to avoid any confusion when running with +heap.

[Dan Kegel]

Hey, on that topic, there are also a bunch of other possible suspects:

./dlls/ntdll/tests/atom.c:    memset(abi->Name, 0x55, 255 * sizeof(WCHAR));
./dlls/ntdll/tests/atom.c:    memset(abi->Name, 0x55,
lstrlenW(testAtom1) * sizeof(WCHAR));
./dlls/user32/tests/menu.c:    memset( bmfill, 0x55, sizeof( bmfill));
./dlls/ntoskrnl.exe/ntoskrnl.c:    memset( &irp, 0x55, sizeof(irp) );
./tools/wrc/utils.c:    memset(res, 0x55, size);
./tools/widl/utils.c:    memset(res, 0x55, size);
./tools/wmc/utils.c:    memset(res, 0x55, size);
./server/object.c:    if (ptr) memset( ptr, 0x55, size );
./server/window.c:    memset( win, 0x55, sizeof(*win) +
win->nb_extra_bytes - 1 );

And 0xaa can also interfere:

./dlls/kernel32/tests/process.c:    memset(&info, 0xaa, sizeof(info));
./dlls/ddraw/tests/d3d.c:    memset(outH, 0xaa, sizeof(outH));
./dlls/comctl32/tests/listview.c:    memset(&column, 0xaa, sizeof(column));
./dlls/comctl32/tests/listview.c:    memset(&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset (&item, 0xaa, sizeof (item));
./dlls/comctl32/tests/listview.c:    memset(&column, 0xaa, sizeof(column));
./server/object.c:        memset( obj, 0xaa, obj->ops->size );