fix: improve cache state clearing and average calculation logic

steamcache/avgcachestate/avgcachestate.go

@@ -26,7 +26,9 @@ func (a *AvgCacheState) Clear() {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
-	a.avgs = make([]cachestate.CacheState, a.size) // zeroed
+	for i := 0; i < len(a.avgs); i++ {
+		a.avgs[i] = cachestate.CacheStateMiss
+	}
 }
 
 // Add adds a cache state to the average cache state.
@@ -45,16 +47,13 @@ func (a *AvgCacheState) Avg() float64 {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
-	var hits, misses int
+	var hits int
 	for _, cs := range a.avgs {
 		switch cs {
 		case cachestate.CacheStateHit:
 			hits++
-		case cachestate.CacheStateMiss:
-			misses++
 		}
 	}
-	total := hits + misses
 
-	return float64(hits) / float64(total)
+	return float64(hits) / float64(len(a.avgs))
 }