cppcheck: fixes issues found for plugins/compress
cppcheck: fixes issues found for plugins/compress

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