accounts/abi: fix staticcheck warnings (ethereum#20358)

* accounts/abi: fix staticcheck warnings

* accounts/abi: restore unused field for test

accounts/abi/abi_test.go

@@ -927,7 +927,7 @@ func TestABI_MethodById(t *testing.T) {
 		}
 		b := fmt.Sprintf("%v", m2)
 		if a != b {
-			t.Errorf("Method %v (id %v) not 'findable' by id in ABI", name, common.ToHex(m.ID()))
+			t.Errorf("Method %v (id %x) not 'findable' by id in ABI", name, m.ID())
 		}
 	}
 	// Also test empty

accounts/abi/event_test.go

@@ -173,7 +173,7 @@ func TestEventTupleUnpack(t *testing.T) {
 	type EventTransferWithTag struct {
 		// this is valid because `value` is not exportable,
 		// so value is only unmarshalled into `Value1`.
-		value  *big.Int
+		value  *big.Int //lint:ignore U1000 unused field is part of test
 		Value1 *big.Int `abi:"value"`
 	}
 
@@ -354,40 +354,6 @@ func unpackTestEventData(dest interface{}, hexData string, jsonEvent []byte, ass
 	return a.Unpack(dest, "e", data)
 }
 
-/*
-Taken from
-https://github.com/ethereum/go-ethereum/pull/15568
-*/
-
-type testResult struct {
-	Values [2]*big.Int
-	Value1 *big.Int
-	Value2 *big.Int
-}
-
-type testCase struct {
-	definition string
-	want       testResult
-}
-
-func (tc testCase) encoded(intType, arrayType Type) []byte {
-	var b bytes.Buffer
-	if tc.want.Value1 != nil {
-		val, _ := intType.pack(reflect.ValueOf(tc.want.Value1))
-		b.Write(val)
-	}
-
-	if !reflect.DeepEqual(tc.want.Values, [2]*big.Int{nil, nil}) {
-		val, _ := arrayType.pack(reflect.ValueOf(tc.want.Values))
-		b.Write(val)
-	}
-	if tc.want.Value2 != nil {
-		val, _ := intType.pack(reflect.ValueOf(tc.want.Value2))
-		b.Write(val)
-	}
-	return b.Bytes()
-}
-
 // TestEventUnpackIndexed verifies that indexed field will be skipped by event decoder.
 func TestEventUnpackIndexed(t *testing.T) {
 	definition := `[{"name": "test", "type": "event", "inputs": [{"indexed": true, "name":"value1", "type":"uint8"},{"indexed": false, "name":"value2", "type":"uint8"}]}]`