dmusic: Constify a variable

[Andrew Talbot]

Changelog:
    dmusic: Constify a variable.

diff --git a/dlls/dmusic/dmusic_main.c b/dlls/dmusic/dmusic_main.c
index 9c0e78f..6cd92ab 100644
--- a/dlls/dmusic/dmusic_main.c
+++ b/dlls/dmusic/dmusic_main.c
@@ -187,7 +187,7 @@ HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
  *
  */
 /* dwPatch from MIDILOCALE */
-DWORD MIDILOCALE2Patch (LPMIDILOCALE pLocale) {
+DWORD MIDILOCALE2Patch (const MIDILOCALE *pLocale) {
 	DWORD dwPatch = 0;
 	if (!pLocale) return 0;
 	dwPatch |= (pLocale->ulBank & F_INSTRUMENT_DRUMS); /* set drum bit */
diff --git a/dlls/dmusic/dmusic_private.h b/dlls/dmusic/dmusic_private.h
index 2de7e8a..e7668a4 100644
--- a/dlls/dmusic/dmusic_private.h
+++ b/dlls/dmusic/dmusic_private.h
@@ -266,7 +266,7 @@ typedef struct {
 #define GE(x) { &x, #x }
 
 /* dwPatch from MIDILOCALE */
-extern DWORD MIDILOCALE2Patch (LPMIDILOCALE pLocale);
+extern DWORD MIDILOCALE2Patch (const MIDILOCALE *pLocale);
 /* MIDILOCALE from dwPatch */
 extern void Patch2MIDILOCALE (DWORD dwPatch, LPMIDILOCALE pLocale);