Remove error returned by Msg and Msgf

When error happen, there is nothing the caller can really do and it is
not practicle to handle logging errors. Print an error on the standard
error instead.

event.go

@@ -3,6 +3,7 @@ package zerolog
 import (
 	"fmt"
 	"io/ioutil"
+	"os"
 	"sync"
 	"time"
 )
@@ -58,9 +59,9 @@ func (e *Event) Enabled() bool {
 //
 // NOTICE: once this method is called, the *Event should be disposed.
 // Calling Msg twice can have unexpected result.
-func (e *Event) Msg(msg string) error {
+func (e *Event) Msg(msg string) {
 	if !e.enabled {
-		return nil
+		return
 	}
 	if msg != "" {
 		e.buf = appendString(e.buf, MessageFieldName, msg)
@@ -68,16 +69,18 @@ func (e *Event) Msg(msg string) error {
 	if e.done != nil {
 		defer e.done(msg)
 	}
-	return e.write()
+	if err := e.write(); err != nil {
+		fmt.Fprintf(os.Stderr, "zerolog: could not write event: %v", err)
+	}
 }
 
 // Msgf sends the event with formated msg added as the message field if not empty.
 //
 // NOTICE: once this methid is called, the *Event should be disposed.
 // Calling Msg twice can have unexpected result.
-func (e *Event) Msgf(format string, v ...interface{}) error {
+func (e *Event) Msgf(format string, v ...interface{}) {
 	if !e.enabled {
-		return nil
+		return
 	}
 	msg := fmt.Sprintf(format, v...)
 	if msg != "" {
@@ -86,7 +89,9 @@ func (e *Event) Msgf(format string, v ...interface{}) error {
 	if e.done != nil {
 		defer e.done(msg)
 	}
-	return e.write()
+	if err := e.write(); err != nil {
+		fmt.Fprintf(os.Stderr, "zerolog: could not write event: %v", err)
+	}
 }
 
 // Dict adds the field key with a dict to the event context.

log.go

@@ -264,7 +264,7 @@ func (l Logger) Write(p []byte) (n int, err error) {
 		// Trim CR added by stdlog.
 		p = p[0 : n-1]
 	}
-	err = l.Log().Msg(string(p))
+	l.Log().Msg(string(p))
 	return
 }