make: unifdef for other OSes (undefined)

@@ -93,13 +93,10 @@
         Name            done;
         Name            dot;
         Name            dot_keep_state;
         Name            dot_keep_state_file;
         Name            empty_name;
-#if defined(HP_UX) ||  defined(linux)
-        int             exit_status;
-#endif
         Boolean         fatal_in_progress;
         int             file_number;
 #if 0
         Boolean         filter_stderr;                  /* `-X' */
 #endif