use syslog for mpd

package/mpd/files/mpd.conf

@@ -4,7 +4,7 @@ music_directory			"/music"
 playlist_directory		"~/playlists"
 db_file				"~/.database"
 pid_file			"/var/run/mpd/mpd.pid"
-log_file			"~/.log"
+log_file			syslog
 # An example of an ALSA output
 audio_output {
 	type			"alsa"