OS-1572 Explicitly handle all possible enum values in switches
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 253,262 ****
--- 253,264 ----
                          case ZONE_IS_DOWN:
                          case ZONE_IS_DYING:
                          case ZONE_IS_DEAD:
                                  /* FALLTHRU */
                                  continue;
+                         default:
+                                 break;
                  }
                  if ((res = dlmgmt_zone_init(zids[i])) != 0) {
                          (void) fprintf(stderr, "zone (%ld) init error %s",
                              zids[i], strerror(res));
                          dlmgmt_log(LOG_ERR, "zone (%d) init error %s",