Fix analyzeLatencyForEvent() MAD computation.
Fix analyzeLatencyForEvent() MAD computation.

MSOpenTech/redis,ttuna/msot-redis,HunanTV/redis,louisliangjun/redis,xuzhezhaozhao/redis_reading,xuzhezhaozhao/redis_reading,ttuna/msot-redis,slfs007/mk-redis,louisliangjun/redis,ttuna/msot-redis,ramonsnir/redis,himoca/redis,xuzhezhaozhao/redis_reading,xuzhezhaozhao/redis_reading,ramonsnir/redis,HunanTV/redis,slfs007/mk-redis,ramonsnir/redis,darksideofthemoo/redis-histogram,HunanTV/redis,louisliangjun/redis,ksarch-saas/redis,ttuna/msot-redis,darksideofthemoo/redis-histogram,maodeyi/redis_lua,MSOpenTech/redis,splitice/redis,maodeyi/redis_lua,louisliangjun/redis,ttuna/msot-redis,splitice/redis,MSOpenTech/redis,spearhead-ea/redis,ksarch-saas/redis,jxwr/redis,spearhead-ea/redis,himoca/redis,MSOpenTech/redis,maodeyi/redis_lua,jxwr/redis,darksideofthemoo/redis-histogram,MSOpenTech/redis,ksarch-saas/redis,slfs007/mk-redis,splitice/redis,spearhead-ea/redis,himoca/redis,splitice/redis,ksarch-saas/redis,darksideofthemoo/redis-histogram,HunanTV/redis,jxwr/redis