db/simple/Song: convert NewFrom() to constructor

src/db/plugins/simple/DirectorySave.cxx

@@ -165,8 +165,8 @@ directory_load(TextFile &file, Directory &directory)
 			auto detached_song = song_load(file, name,
 						       &audio_format);
 
-			auto song = Song::NewFrom(std::move(*detached_song),
-						  directory);
+			auto song = std::make_unique<Song>(std::move(*detached_song),
+							   directory);
 			song->audio_format = audio_format;
 
 			directory.AddSong(std::move(song));

src/db/plugins/simple/Song.cxx

@@ -31,21 +31,14 @@ Song::Song(StringView _uri, Directory &_parent) noexcept
 {
 }
 
-static SongPtr
-song_alloc(StringView uri, Directory &parent) noexcept
+Song::Song(DetachedSong &&other, Directory &_parent) noexcept
+	:tag(std::move(other.WritableTag())),
+	 parent(_parent),
+	 mtime(other.GetLastModified()),
+	 start_time(other.GetStartTime()),
+	 end_time(other.GetEndTime()),
+	 uri(other.GetURI())
 {
-	return std::make_unique<Song>(uri, parent);
-}
-
-SongPtr
-Song::NewFrom(DetachedSong &&other, Directory &parent) noexcept
-{
-	SongPtr song(song_alloc(other.GetURI(), parent));
-	song->tag = std::move(other.WritableTag());
-	song->mtime = other.GetLastModified();
-	song->start_time = other.GetStartTime();
-	song->end_time = other.GetEndTime();
-	return song;
 }
 
 std::string

src/db/plugins/simple/Song.hxx

@@ -99,7 +99,7 @@ struct Song {
 
 	Song(StringView _uri, Directory &parent) noexcept;
 
-	static SongPtr NewFrom(DetachedSong &&other, Directory &parent) noexcept;
+	Song(DetachedSong &&other, Directory &_parent) noexcept;
 
 	/**
 	 * allocate a new song structure with a local file name and attempt to

src/db/update/Container.cxx

@@ -69,7 +69,8 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 		}
 
 		for (auto &vtrack : v) {
-			auto song = Song::NewFrom(std::move(vtrack), *contdir);
+			auto song = std::make_unique<Song>(std::move(vtrack),
+							   *contdir);
 
 			// shouldn't be necessary but it's there..
 			song->mtime = info.mtime;