packet_buffer.cc: Removed #include of iostream.

A silly little mistake that broke upstream.

NOTRY=True
TBR=kwiberg@webrtc.org

Review URL: https://codereview.webrtc.org/2306613002 .

Cr-Original-Commit-Position: refs/heads/master@{#14025}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: a0e60e8550a11ae78136b590c91d0de5a27436cb
diff --git a/modules/audio_coding/neteq/payload_splitter.cc b/modules/audio_coding/neteq/payload_splitter.cc
index 87d2ce5..a561440 100644
--- a/modules/audio_coding/neteq/payload_splitter.cc
+++ b/modules/audio_coding/neteq/payload_splitter.cc
@@ -11,7 +11,6 @@
 #include "webrtc/modules/audio_coding/neteq/payload_splitter.h"
 
 #include <assert.h>
-#include <iostream>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"