Fix memory leak in traffic_cache_tool.
Fix memory leak in traffic_cache_tool.

Coverity 1390802

pbchou/trafficserver,duke8253/trafficserver,davidbz/trafficserver,davidbz/trafficserver,davidbz/trafficserver,davidbz/trafficserver,SolidWallOfCode/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,bryancall/trafficserver,duke8253/trafficserver,bryancall/trafficserver,duke8253/trafficserver,davidbz/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,davidbz/trafficserver,SolidWallOfCode/trafficserver,dyrock/trafficserver,pbchou/trafficserver,pbchou/trafficserver,chitianhao/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,dyrock/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,chitianhao/trafficserver,bryancall/trafficserver,chitianhao/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,duke8253/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,dyrock/trafficserver,chitianhao/trafficserver,dyrock/trafficserver,chitianhao/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,pbchou/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver