tlv: remove unused error return value

This commit also modifies a previous migration. Because the change is so
limited, we don't consider this a significant risk.

tlv/record.go

@@ -219,7 +219,7 @@ func StubEncoder(v []byte) Encoder {
 // MapToRecords encodes the passed TLV map as a series of regular tlv.Record
 // instances. The resulting set of records will be returned in sorted order by
 // their type.
-func MapToRecords(tlvMap map[uint64][]byte) ([]Record, error) {
+func MapToRecords(tlvMap map[uint64][]byte) []Record {
 	records := make([]Record, 0, len(tlvMap))
 	for k, v := range tlvMap {
 		// We don't pass in a decoder here since we don't actually know
@@ -234,7 +234,7 @@ func MapToRecords(tlvMap map[uint64][]byte) ([]Record, error) {
 
 	SortRecords(records)
 
-	return records, nil
+	return records
 }
 
 // SortRecords is a helper function that will sort a slice of records in place

tlv/record_test.go

@@ -114,10 +114,7 @@ func TestRecordMapTransformation(t *testing.T) {
 				spew.Sdump(mappedRecords))
 		}
 
-		unmappedRecords, err := MapToRecords(mappedRecords)
-		if err != nil {
-			t.Fatalf("#%v: unable to unmap records: %v", i, err)
-		}
+		unmappedRecords := MapToRecords(mappedRecords)
 
 		for i := 0; i < len(testCase.records); i++ {
 			if unmappedRecords[i].Type() != testCase.records[i].Type() {