Use backticks not vertical bars to denote variables in comments for /modules/rtp_rtcp

Bug: webrtc:12338
Change-Id: I52eb3b6675c4705e22f51b70799ed6139a3b46bc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227164
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34686}
diff --git a/modules/rtp_rtcp/source/rtp_rtcp_impl.h b/modules/rtp_rtcp/source/rtp_rtcp_impl.h
index 45cfdb4..c5d0b3a 100644
--- a/modules/rtp_rtcp/source/rtp_rtcp_impl.h
+++ b/modules/rtp_rtcp/source/rtp_rtcp_impl.h
@@ -279,7 +279,7 @@
     // Handles final time timestamping/stats/etc and handover to Transport.
     DEPRECATED_RtpSenderEgress packet_sender;
     // If no paced sender configured, this class will be used to pass packets
-    // from |packet_generator_| to |packet_sender_|.
+    // from `packet_generator_` to `packet_sender_`.
     DEPRECATED_RtpSenderEgress::NonPacedPacketSender non_paced_sender;
     // Handles creation of RTP packets to be sent.
     RTPSender packet_generator;