pixma: document falling through to next switch case

backend/pixma_bjnp.c

@@ -2315,6 +2315,8 @@ sanei_bjnp_read_int (SANE_Int dn, SANE_Byte * buffer, size_t * size)
         }
       device[dn].polling_status = BJNP_POLL_STARTED;
 
+      /* fall through to BJNP_POLL_STARTED */
+
     case BJNP_POLL_STARTED:
       /* we use only seonds accuracy between poll attempts */
       timeout = device[dn].bjnp_timeout /1000;