decoder/dsdiff: use PackedBE64 instead of DffDsdUint64

src/decoder/plugins/DsdLib.hxx

@@ -31,17 +31,6 @@ public:
 	}
 };
 
-class DffDsdUint64 {
-	uint32_t hi;
-	uint32_t lo;
-
-public:
-	constexpr uint64_t Read() const {
-		return (uint64_t(FromBE32(hi)) << 32) |
-			uint64_t(FromBE32(lo));
-	}
-};
-
 bool
 dsdlib_skip_to(DecoderClient *client, InputStream &is,
 	       offset_type offset);

src/decoder/plugins/DsdiffDecoderPlugin.cxx

@@ -22,13 +22,13 @@
 
 struct DsdiffHeader {
 	DsdId id;
-	DffDsdUint64 size;
+	PackedBE64 size;
 	DsdId format;
 };
 
 struct DsdiffChunkHeader {
 	DsdId id;
-	DffDsdUint64 size;
+	PackedBE64 size;
 
 	/**
 	 * Read the "size" attribute from the specified header, converting it
@@ -36,7 +36,7 @@ struct DsdiffChunkHeader {
 	 */
 	[[nodiscard]] constexpr
 	uint64_t GetSize() const {
-		return size.Read();
+		return size;
 	}
 
 	/**