user32: Fix the scope of a local variable.

dlls/user32/message.c

@@ -1999,6 +1999,7 @@ static BOOL post_dde_message( struct packed_message *data, const struct send_mes
     HGLOBAL     hunlock = 0;
     int         i;
     DWORD       res;
+    ULONGLONG   hpack;
 
     if (!UnpackDDElParam( info->msg, info->lparam, &uiLo, &uiHi ))
         return FALSE;
@@ -2019,7 +2020,7 @@ static BOOL post_dde_message( struct packed_message *data, const struct send_mes
             HGLOBAL h = dde_get_pair( (HANDLE)uiHi );
             if (h)
             {
-                ULONGLONG hpack = pack_ptr( h );
+                hpack = pack_ptr( h );
                 /* send back the value of h on the other side */
                 push_data( data, &hpack, sizeof(hpack) );
                 lp = uiLo;