msacm32: Mark fall-through in switch statement

[Andrew Talbot]

Changelog:
    msacm32: Mark fall-through in switch statement.

diff --git a/dlls/msacm32/msacm32_main.c b/dlls/msacm32/msacm32_main.c
index d3160e3..6552812 100644
--- a/dlls/msacm32/msacm32_main.c
+++ b/dlls/msacm32/msacm32_main.c
@@ -87,6 +87,7 @@ DWORD WINAPI acmGetVersion(void)
 	return 0x04000565; /* 4.0.1381 */
     default:
         FIXME("%x not supported\n", version.dwPlatformId);
+        /* fall through */
     case VER_PLATFORM_WIN32_WINDOWS:
 	return 0x04030000; /* 4.3.0 */
     }