XXXX pass in cpu_pause_func via pause_cpus

*** 277,287 ****
           * Pause all working CPUs, which ensures that there's no CPU in
           * function xc_common().
           * This is used to work around a race condition window in xc_common()
           * between checking CPU_READY flag and increasing working item count.
           */
!         pause_cpus(cpup);
          start_cpus();
  
          for (i = 0; i < XC_FLUSH_MAX_WAITS; i++) {
                  if (cpup->cpu_m.xc_work_cnt == 0) {
                          break;
--- 277,287 ----
           * Pause all working CPUs, which ensures that there's no CPU in
           * function xc_common().
           * This is used to work around a race condition window in xc_common()
           * between checking CPU_READY flag and increasing working item count.
           */
!         pause_cpus(cpup, NULL);
          start_cpus();
  
          for (i = 0; i < XC_FLUSH_MAX_WAITS; i++) {
                  if (cpup->cpu_m.xc_work_cnt == 0) {
                          break;