LOCAL: devfs_clean before trying to offline to release refs to dev_info

*** 5888,5897 ****
--- 5888,5904 ----
                              &cookie) == NDI_SUCCESS)
                                  (void) ndi_post_event(dip, dip, cookie, NULL);
                  }
          }
  
+         /*
+          * dv_mknod places a hold on the dev_info_t for each devfs node
+          * created.  If we're to succeed in detaching this device, we must
+          * first release all outstanding references held by devfs.
+          */
+         (void) devfs_clean(pdip, NULL, DV_CLEAN_FORCE);
+ 
          if (i_ddi_detachchild(dip, flags) != DDI_SUCCESS) {
                  if (flags & NDI_DEVI_OFFLINE) {
                          RIO_DEBUG((CE_NOTE, "devi_detach_node: offline failed."
                              " Calling e_ddi_offline_finalize with result=%d. "
                              "dip=%p", DDI_FAILURE, (void *)dip));