[debugger] Remove unused error condition

I noticed the error condition was incorrect, so the warning log was not
being printed anyway. The client code will choose whether or not to
display the error in the status field of the reply.

Change-Id: I40d7991a782c6018be022c49b5654f1961db0137
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1152475
Fuchsia-Auto-Submit: Jacob Rutherford <[email protected]>
Reviewed-by: Adam Barth <[email protected]>
Commit-Queue: Auto-Submit <[email protected]>

Author: Sandlot19

src/developer/debug/debug_agent/debug_agent.cc

@@ -766,9 +766,6 @@ void DebugAgent::OnAttach(const debug_ipc::AttachRequest& request, debug_ipc::At
   if (request.config.target == debug_ipc::AttachConfig::Target::kJob) {
     if (!IsAttachedToParentOrAncestorOf(request.koid)) {
       reply->status = AttachToExistingJob(request.koid, request.config, reply);
-      if (reply->status.ok()) {
-        DEBUG_LOG(Agent) << "Could not attach to job: " << reply->status.message();
-      }
     } else {
       reply->status =
           debug::Status(debug::Status::kAlreadyExists, "Already attached to ancestor job.");