Fix some inline parameter name comments.

The name of this parameter recently changed in https://github.com/google/ExoPlayer/commit/3fe0b1a6fee8e7631caa5a6f84306396ee6999ad and I forgot
to change these inline comment usages.

PiperOrigin-RevId: 258160659

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java

@@ -442,7 +442,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
     loadControl.onPrepared();
     this.mediaSource = mediaSource;
     setState(Player.STATE_BUFFERING);
-    mediaSource.prepareSource(/* listener= */ this, bandwidthMeter.getTransferListener());
+    mediaSource.prepareSource(/* caller= */ this, bandwidthMeter.getTransferListener());
     handler.sendEmptyMessage(MSG_DO_SOME_WORK);
   }
 
@@ -914,7 +914,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
             startPositionUs);
     if (releaseMediaSource) {
       if (mediaSource != null) {
-        mediaSource.releaseSource(/* listener= */ this);
+        mediaSource.releaseSource(/* caller= */ this);
         mediaSource = null;
       }
     }

library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadHelper.java

@@ -852,7 +852,7 @@ public final class DownloadHelper {
     public boolean handleMessage(Message msg) {
       switch (msg.what) {
         case MESSAGE_PREPARE_SOURCE:
-          mediaSource.prepareSource(/* listener= */ this, /* mediaTransferListener= */ null);
+          mediaSource.prepareSource(/* caller= */ this, /* mediaTransferListener= */ null);
           mediaSourceHandler.sendEmptyMessage(MESSAGE_CHECK_FOR_FAILURE);
           return true;
         case MESSAGE_CHECK_FOR_FAILURE: