support current JSON::XS version, diff from FreeBSD ports.

$OpenBSD: patch-Slim_Plugin_LastFM_ProtocolHandler_pm,v 1.2 2009/01/28 01:36:00 sthen Exp $
--- Slim/Plugin/LastFM/ProtocolHandler.pm.orig	Tue Jan 20 02:35:14 2009
+++ Slim/Plugin/LastFM/ProtocolHandler.pm	Wed Jan 21 01:28:36 2009
@@ -7,7 +7,7 @@ package Slim::Plugin::LastFM::ProtocolHandler;
 use strict;
 use base qw(Slim::Player::Protocols::HTTP);
 
-use JSON::XS qw(from_json);
+use JSON::XS qw(decode_json);
 use URI::Escape qw(uri_escape_utf8);
 
 use Slim::Player::Playlist;
@@ -141,7 +141,7 @@ sub _gotNextTrack {
 	my $client = $http->params->{client};
 	my $params = $http->params->{params};
 	
-	my $track = eval { from_json( $http->content ) };
+	my $track = eval { decode_json( $http->content ) };
 	
 	if ( $@ || $track->{error} ) {
 		# We didn't get the info to play