Fix crash when exporting packet dissection as plain text on Windows (regression introduced in r45333)

svn path=/trunk/; revision=45378

ui/win32/file_dlg_win32.c

@@ -2165,6 +2165,8 @@ export_file_hook_proc(HWND ef_hwnd, UINT msg, WPARAM w_param, LPARAM l_param) {
 
     switch(msg) {
         case WM_INITDIALOG:
+            /* init the printing range */
+            packet_range_init(&print_args.range, &cfile);
             /* default to displayed packets */
             print_args.range.process_filtered = TRUE;
             range_handle_wm_initdialog(ef_hwnd, &print_args.range);