fix for -fno-common
https://gitweb.gentoo.org/repo/gentoo.git/commit/media-sound/scmpc/files?id=c9f42ac8feb314f3f2f6ec7cfd8c535ff33fe735

Index: src/mpd.c
--- src/mpd.c.orig
+++ src/mpd.c
@@ -37,6 +37,8 @@ static void mpd_schedule_check(void);
 static gboolean mpd_parse(GIOChannel *source, GIOCondition condition,
 		gpointer data);
 
+struct mpd_t mpd;
+
 gboolean mpd_connect(void)
 {
 	mpd.conn = mpd_connection_new(prefs.mpd_hostname, prefs.mpd_port,