[#86] engine: Simplify multiple chains processing

So, it's sunday evening and I am sitting on-call trying to debug strange
node behaviour. It took me 3 whole minutes to understand the code being
changed: it accumulates bools in slices, even though no slice is needed;
it uses subtle condition from the first loop to make decision in the
second one, and finally it uses named return values.

In this commit we remove the slice and the second loop, because why not.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/engine/chain_router.go

@@ -42,41 +42,36 @@ func (dr *defaultChainRouter) checkLocal(name chain.Name, rt RequestTarget, r re
 	if dr.local == nil {
 		return
 	}
-	var ruleFounds []bool
+
+	var hasAllow bool
 	for _, target := range rt.Targets() {
 		status, ruleFound, err = dr.matchLocalOverrides(name, target, r)
 		if err != nil || ruleFound && status != chain.Allow {
 			return
 		}
-		ruleFounds = append(ruleFounds, ruleFound)
+		hasAllow = hasAllow || ruleFound
 	}
 
 	status = chain.NoRuleFound
-	for _, ruleFound = range ruleFounds {
+	if hasAllow {
-		if ruleFound {
 		status = chain.Allow
-			break
-		}
 	}
 	return
 }
 
 func (dr *defaultChainRouter) checkMorph(name chain.Name, rt RequestTarget, r resource.Request) (status chain.Status, ruleFound bool, err error) {
-	var ruleFounds []bool
+	var hasAllow bool
 	for _, target := range rt.Targets() {
 		status, ruleFound, err = dr.matchMorphRuleChains(name, target, r)
 		if err != nil || ruleFound && status != chain.Allow {
 			return
 		}
-		ruleFounds = append(ruleFounds, ruleFound)
+		hasAllow = hasAllow || ruleFound
 	}
 
 	status = chain.NoRuleFound
-	for _, ruleFound = range ruleFounds {
+	if hasAllow {
-		if ruleFound {
 		status = chain.Allow
-			break
-		}
 	}
 	return
 }