InputStream: add virtual destructor

Replaces the method Close().

src/playlist/CloseSongEnumerator.cxx

@@ -24,7 +24,7 @@
 CloseSongEnumerator::~CloseSongEnumerator()
 {
 	delete other;
-	is->Close();
+	delete is;
 }
 
 DetachedSong *

src/playlist/PlaylistStream.cxx

@@ -50,7 +50,7 @@ playlist_open_path_suffix(const char *path_fs, Mutex &mutex, Cond &cond)
 	if (playlist != nullptr)
 		playlist = new CloseSongEnumerator(playlist, is);
 	else
-		is->Close();
+		delete is;
 
 	return playlist;
 }
@@ -85,7 +85,7 @@ playlist_open_remote(const char *uri, Mutex &mutex, Cond &cond)
 
 	playlist = playlist_list_open_stream(*is, uri);
 	if (playlist == nullptr) {
-		is->Close();
+		delete is;
 		return nullptr;
 	}
 

src/playlist/plugins/SoundCloudPlaylistPlugin.cxx

@@ -276,7 +276,7 @@ soundcloud_parse_json(const char *url, yajl_handle hand,
 				done = true;
 			} else {
 				mutex.unlock();
-				input_stream->Close();
+				delete input_stream;
 				return -1;
 			}
 		}
@@ -304,7 +304,7 @@ soundcloud_parse_json(const char *url, yajl_handle hand,
 	}
 
 	mutex.unlock();
-	input_stream->Close();
+	delete input_stream;
 
 	return 0;
 }