ref: improve os name code

fetch/os.go

@@ -22,14 +22,11 @@ func Os() (string, error) {
 
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
-		s := scanner.Text()
-		if strings.HasPrefix(s, linePrefix) {
-			return strings.TrimPrefix(
-				strings.TrimSuffix(
-					strings.TrimPrefix(s, linePrefix),
-					`"`,
-				), `"`,
-			), nil
+		line := scanner.Text()
+
+		if strings.HasPrefix(line, linePrefix) {
+			line = strings.TrimPrefix(line, linePrefix)
+			return strings.Trim(line, "\""), nil
 		}
 	}