Fixes build issue

formatters/json_formatter.go

@@ -52,11 +52,11 @@ func (f JSONFormatter) Format(level log.Level, msg string, logger *log.Logger) [
 	data["line"] = line
 	data["msg"] = msg
 
-	line, err := marshal(data)
+	serialized, err := marshal(data)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Failed to marshal json, %v\n", err)
 	}
-	return line
+	return serialized
 }
 
 func marshal(v interface{}) ([]byte, error) {

formatters/text_formatter.go

@@ -2,7 +2,6 @@ package formatters
 
 import (
 	"bytes"
-	"io"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -49,7 +48,7 @@ func (f TextFormatter) Format(level log.Level, msg string, logger *log.Logger) [
 
 		f.isterm = IsTerminal(logger.Out)
 
-		host, _ = os.Hostname()
+		host, _ := os.Hostname()
 		f.host = []byte(host)
 
 		f.pid = []byte(strconv.Itoa(os.Getpid()))

formatters/util_terminal.go

@@ -1,6 +1,9 @@
 package formatters
 
 import (
+	"io"
+	"os"
+
 	"golang.org/x/crypto/ssh/terminal"
 )