upgrade golangci-lint to v1.40.1 (#10276)

Also: fix linter issue detected with newer version

.circleci/config.yml

@@ -126,7 +126,7 @@ jobs:
           name: Install golangci-lint
           command: |
             download=https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh
-            wget -O- -q $download | sh -x -s -- -d -b /go/bin/ v1.23.6
+            wget -O- -q $download | sh -x -s -- -d -b /go/bin/ v1.40.1
       - run: go mod download
       - run:
           name: lint

GNUmakefile

@@ -8,7 +8,7 @@ GOTOOLS = \
 	github.com/gogo/protobuf/protoc-gen-gofast@$(GOGOVERSION) \
 	github.com/hashicorp/protoc-gen-go-binary \
 	github.com/vektra/mockery/cmd/mockery \
-	github.com/golangci/golangci-lint/cmd/golangci-lint@v1.23.6
+	github.com/golangci/golangci-lint/cmd/golangci-lint@v1.40.1
 
 GOTAGS ?=
 GOOS?=$(shell go env GOOS)

agent/dns.go

@@ -1429,18 +1429,16 @@ func (d *DNSServer) serviceNodeRecords(cfg *dnsConfig, dc string, nodes structs.
 		}
 		handled[records[0].String()] = struct{}{}
 
-		if records != nil {
-			switch records[0].(type) {
-			case *dns.CNAME:
-				// keep track of the first CNAME + associated RRs but don't add to the resp.Answer yet
-				// this will only be added if no non-CNAME RRs are found
-				if len(answerCNAME) == 0 {
-					answerCNAME = records
-				}
-			default:
-				resp.Answer = append(resp.Answer, records...)
-				had_answer = true
+		switch records[0].(type) {
+		case *dns.CNAME:
+			// keep track of the first CNAME + associated RRs but don't add to the resp.Answer yet
+			// this will only be added if no non-CNAME RRs are found
+			if len(answerCNAME) == 0 {
+				answerCNAME = records
 			}
+		default:
+			resp.Answer = append(resp.Answer, records...)
+			had_answer = true
 		}
 
 		if had_answer {