Remove deprecated ChannelOutput argument

Change-Id: Ic65def386f6bfe9c16045facbce9dae05e99b8bd
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/108985
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Alexei Frolov <frolv@google.com>
Pigweed-Auto-Submit: Taylor Cramer <cramertj@google.com>
diff --git a/applications/rpc/main.cc b/applications/rpc/main.cc
index f75b81d..c53ba64 100644
--- a/applications/rpc/main.cc
+++ b/applications/rpc/main.cc
@@ -129,7 +129,7 @@
 
   // Packet was validated and correct (CRC, etc); so send it to the RPC server.
   // The RPC server may send response packets before returning from this call.
-  server.ProcessPacket(hdlc_frame.data(), hdlc_channel_output);
+  server.ProcessPacket(hdlc_frame.data());
 }
 
 // TODO FOR WORKSHOP: Add an RPC to change the blink time.