lib/xiph/OggVisitor: invoke OnOggPacket() with the "E_O_S" packet

The "end of stream" packet is not special; it contains normal data,
and thus we should pass it to OnOggPacket().

This fixes one part of https://github.com/MusicPlayerDaemon/MPD/issues/601

NEWS

@@ -1,6 +1,7 @@
 ver 0.21.12 (not yet released)
 * decoder
   - opus: ignore case in replay gain tag names
+  - opus, vorbis: decode the "end of stream" packet
 * Windows
   - support backslash in relative URIs loaded from playlists
 

src/lib/xiph/OggVisitor.cxx

@@ -69,12 +69,12 @@ OggVisitor::HandlePacket(const ogg_packet &packet)
 		/* fail if BOS is missing */
 		throw std::runtime_error("BOS packet expected");
 
+	OnOggPacket(packet);
+
 	if (packet.e_o_s) {
 		EndStream();
 		return;
 	}
-
-	OnOggPacket(packet);
 }
 
 inline void