audio_buffers: Pass by const-ref in AppendBuffers

This function doesn't modify the passed in buffer, so we can make that
explicit.

src/audio_core/device/audio_buffers.h

@@ -36,7 +36,7 @@ public:
      *
      * @param buffer - The new buffer.
      */
-    void AppendBuffer(AudioBuffer& buffer) {
+    void AppendBuffer(const AudioBuffer& buffer) {
         std::scoped_lock l{lock};
         buffers[appended_index] = buffer;
         appended_count++;

src/audio_core/in/audio_in_system.cpp

@@ -114,12 +114,14 @@ bool System::AppendBuffer(const AudioInBuffer& buffer, const u64 tag) {
     }
 
     const auto timestamp{buffers.GetNextTimestamp()};
-    AudioBuffer new_buffer{.start_timestamp = timestamp,
-                           .end_timestamp = timestamp + buffer.size / (channel_count * sizeof(s16)),
-                           .played_timestamp = 0,
-                           .samples = buffer.samples,
-                           .tag = tag,
-                           .size = buffer.size};
+    const AudioBuffer new_buffer{
+        .start_timestamp = timestamp,
+        .end_timestamp = timestamp + buffer.size / (channel_count * sizeof(s16)),
+        .played_timestamp = 0,
+        .samples = buffer.samples,
+        .tag = tag,
+        .size = buffer.size,
+    };
 
     buffers.AppendBuffer(new_buffer);
     RegisterBuffers();

src/audio_core/out/audio_out_system.cpp

@@ -113,12 +113,14 @@ bool System::AppendBuffer(const AudioOutBuffer& buffer, u64 tag) {
     }
 
     const auto timestamp{buffers.GetNextTimestamp()};
-    AudioBuffer new_buffer{.start_timestamp = timestamp,
-                           .end_timestamp = timestamp + buffer.size / (channel_count * sizeof(s16)),
-                           .played_timestamp = 0,
-                           .samples = buffer.samples,
-                           .tag = tag,
-                           .size = buffer.size};
+    const AudioBuffer new_buffer{
+        .start_timestamp = timestamp,
+        .end_timestamp = timestamp + buffer.size / (channel_count * sizeof(s16)),
+        .played_timestamp = 0,
+        .samples = buffer.samples,
+        .tag = tag,
+        .size = buffer.size,
+    };
 
     buffers.AppendBuffer(new_buffer);
     RegisterBuffers();