[#292] .golangci.yml: Add intrange linter, fix warnings

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

.golangci.yml

@@ -64,5 +64,6 @@ linters:
     - gocognit
     - contextcheck
     - protogetter
+    - intrange
   disable-all: true
   fast: false

eacl/record.go

@@ -286,13 +286,13 @@ func equalRecords(r1, r2 Record) bool {
 		return false
 	}
 
-	for i := range len(fs1) {
+	for i := range fs1 {
 		if !equalFilters(fs1[i], fs2[i]) {
 			return false
 		}
 	}
 
-	for i := range len(ts1) {
+	for i := range ts1 {
 		if !equalTargets(ts1[i], ts2[i]) {
 			return false
 		}

eacl/table.go

@@ -212,7 +212,7 @@ func EqualTables(t1, t2 Table) bool {
 		return false
 	}
 
-	for i := range len(rs1) {
+	for i := range rs1 {
 		if !equalRecords(rs1[i], rs2[i]) {
 			return false
 		}

eacl/target.go

@@ -169,7 +169,7 @@ func equalTargets(t1, t2 Target) bool {
 		return false
 	}
 
-	for i := range len(keys1) {
+	for i := range keys1 {
 		if !bytes.Equal(keys1[i], keys2[i]) {
 			return false
 		}

pool/tree/pool.go

@@ -382,7 +382,7 @@ type SubTreeReader struct {
 
 // Read reads another list of the subtree nodes.
 func (x *SubTreeReader) Read(buf []*grpcService.GetSubTreeResponse_Body) (int, error) {
-	for i := range len(buf) {
+	for i := range buf {
 		resp, err := x.cli.Recv()
 		if err == io.EOF {
 			return i, io.EOF