version: Constify some variables.

dlls/version/info.c

diff --git a/dlls/version/info.c b/dlls/version/info.c
index 56c9cd9..5d4314f 100644
--- a/dlls/version/info.c
+++ b/dlls/version/info.c
@@ -238,7 +238,7 @@
  */
 static DWORD VERSION_GetFileVersionInfo_PE( LPCWSTR filename, DWORD datasize, LPVOID data )
 {
-    VS_FIXEDFILEINFO *vffi;
+    const VS_FIXEDFILEINFO *vffi;
     DWORD len;
     BYTE *buf;
     HMODULE hModule;
@@ -313,7 +313,7 @@
  */
 static DWORD VERSION_GetFileVersionInfo_16( LPCSTR filename, DWORD datasize, LPVOID data )
 {
-    VS_FIXEDFILEINFO *vffi;
+    const VS_FIXEDFILEINFO *vffi;
     DWORD len, offset;
     BYTE *buf;
     HMODULE16 hModule;