riched20: ME_StrDup() is not used anymore so remove it.

dlls/riched20/editor.h

@@ -100,7 +100,6 @@ const char *ME_GetDITypeName(ME_DIType type) DECLSPEC_HIDDEN;
 /* string.c */
 ME_String *ME_MakeStringN(LPCWSTR szText, int nMaxChars) DECLSPEC_HIDDEN;
 ME_String *ME_MakeStringR(WCHAR cRepeat, int nMaxChars) DECLSPEC_HIDDEN;
-ME_String *ME_StrDup(const ME_String *s) DECLSPEC_HIDDEN;
 void ME_DestroyString(ME_String *s) DECLSPEC_HIDDEN;
 BOOL ME_AppendString(ME_String *s, const WCHAR *append, int len) DECLSPEC_HIDDEN;
 ME_String *ME_VSplitString(ME_String *orig, int nVPos) DECLSPEC_HIDDEN;

dlls/riched20/string.c

@@ -59,11 +59,6 @@ ME_String *ME_MakeStringR(WCHAR cRepeat, int nMaxChars)
   return s;
 }
 
-ME_String *ME_StrDup(const ME_String *s)
-{
-  return ME_MakeStringN(s->szData, s->nLen);
-}
-
 void ME_DestroyString(ME_String *s)
 {
   if (!s) return;