util/DynamicFifoBuffer: pass std::span to Append()

src/util/DynamicFifoBuffer.hxx

@@ -109,9 +109,9 @@ public:
 	/**
 	 * Append data to the buffer, growing it as needed.
 	 */
-	void Append(const_pointer p, size_type n) noexcept {
-		std::copy_n(p, n, Write(n));
-		Append(n);
+	void Append(std::span<const std::byte> src) noexcept {
+		std::copy(src.begin(), src.end(), Write(src.size()));
+		Append(src.size());
 	}
 
 protected: