Fixed residency time bug. (Thanks to Sound :-) )

Marlin/Marlin.pde

@@ -737,7 +737,7 @@ inline void process_commands()
           residencyStart = -1;
           /* continue to loop until we have reached the target temp   
             _and_ until TEMP_RESIDENCY_TIME hasn't passed since we reached it */
-          while((target_direction ? (isHeatingHotend0()) : (isCoolingHotend0()) ||
+          while((target_direction ? (isHeatingHotend0()) : (isCoolingHotend0())) ||
                   (residencyStart > -1 && (millis() - residencyStart) < TEMP_RESIDENCY_TIME*1000) ) {
         #else
           while ( target_direction ? (isHeatingHotend0()) : (isCoolingHotend0()) ) {