Fix off-by-one error in DCHECK in ProducerFec.

webrtc/modules/rtp_rtcp/source/producer_fec.cc

Index: webrtc/modules/rtp_rtcp/source/producer_fec.cc
diff --git a/webrtc/modules/rtp_rtcp/source/producer_fec.cc b/webrtc/modules/rtp_rtcp/source/producer_fec.cc
index b928020df3211d33c7a9be5c838b39f49708faa9..941773e6e31e534ea32aa4c46b849f5d0a55bba5 100644
--- a/webrtc/modules/rtp_rtcp/source/producer_fec.cc
+++ b/webrtc/modules/rtp_rtcp/source/producer_fec.cc
@@ -57,7 +57,7 @@ void RedPacket::CreateHeader(const uint8_t* rtp_header,
                              size_t header_length,
                              int red_payload_type,
                              int payload_type) {
-  RTC_DCHECK_LT(header_length + kRedForFecHeaderLength, length_);
+  RTC_DCHECK_LE(header_length + kRedForFecHeaderLength, length_);
   memcpy(data_.get(), rtp_header, header_length);
   // Replace payload type.
   data_[1] &= 0x80;