msi: Fix memory leak in get_fusion_filename (Coverity).

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Hans Leidekker <hans@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

dlls/msi/package.c

@@ -552,6 +552,7 @@ static LPWSTR get_fusion_filename(MSIPACKAGE *package)
         GetWindowsDirectoryW(windir, MAX_PATH);
         len = lstrlenW(windir) + lstrlenW(L"Microsoft.NET\\Framework\\") + lstrlenW(L"v2.0.50727") +
               lstrlenW(L"fusion.dll") + 3;
+        msi_free(filename);
         if (!(filename = msi_alloc(len * sizeof(WCHAR)))) return NULL;
 
         lstrcpyW(filename, windir);