playlist: removed {save,read}PlaylistState()

Those were only wrappers for playlist_state_{save,restore}().  Since
sf_callbacks has been removed, we can call the latter functions
directly.

src/playlist.h

@@ -23,7 +23,6 @@
 #include "queue.h"
 
 #include <stdbool.h>
-#include <stdio.h>
 
 #define PLAYLIST_COMMENT	'#'
 
@@ -116,10 +115,6 @@ playlist_get_queue(const struct playlist *playlist)
 	return &playlist->queue;
 }
 
-void readPlaylistState(FILE *);
-
-void savePlaylistState(FILE *);
-
 void clearPlaylist(struct playlist *playlist);
 
 #ifndef WIN32

src/playlist_global.c

@@ -52,13 +52,3 @@ void finishPlaylist(void)
 {
 	playlist_finish(&g_playlist);
 }
-
-void savePlaylistState(FILE *fp)
-{
-	playlist_state_save(fp, &g_playlist);
-}
-
-void readPlaylistState(FILE *fp)
-{
-	playlist_state_restore(fp, &g_playlist);
-}

src/state_file.c

@@ -20,6 +20,7 @@
 #include "state_file.h"
 #include "output_state.h"
 #include "playlist.h"
+#include "playlist_state.h"
 #include "volume.h"
 
 #include <glib.h>
@@ -52,7 +53,7 @@ state_file_write(void)
 
 	save_sw_volume_state(fp);
 	saveAudioDevicesState(fp);
-	savePlaylistState(fp);
+	playlist_state_save(fp, &g_playlist);
 
 	while(fclose(fp) && errno == EINTR) /* nothing */;
 }
@@ -77,7 +78,7 @@ state_file_read(void)
 	rewind(fp);
 	readAudioDevicesState(fp);
 	rewind(fp);
-	readPlaylistState(fp);
+	playlist_state_restore(fp, &g_playlist);
 
 	while(fclose(fp) && errno == EINTR) /* nothing */;
 }