sunrpc: Re-purpose trace_svc_process

Currently, trace_svc_process has two call sites:

1. Just after a call to svc_send. svc_send already invokes
   trace_svc_send with the same arguments just before returning

2. Just before a call to svc_drop. svc_drop already invokes
   trace_svc_drop with the same arguments just after it is called

Therefore trace_svc_process does not provide any additional
information not already provided by these other trace points.

However, it would be useful to record the incoming RPC procedure.
So reuse trace_svc_process for this purpose.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 387cc4a..f19987f 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1255,6 +1255,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 
 	/* Syntactic check complete */
 	serv->sv_stats->rpccnt++;
+	trace_svc_process(rqstp, progp->pg_name);
 
 	/* Build the reply header. */
 	statp = resv->iov_base +resv->iov_len;
@@ -1431,14 +1432,10 @@ svc_process(struct svc_rqst *rqstp)
 	}
 
 	/* Returns 1 for send, 0 for drop */
-	if (likely(svc_process_common(rqstp, argv, resv))) {
-		int ret = svc_send(rqstp);
+	if (likely(svc_process_common(rqstp, argv, resv)))
+		return svc_send(rqstp);
 
-		trace_svc_process(rqstp, ret);
-		return ret;
-	}
 out_drop:
-	trace_svc_process(rqstp, 0);
 	svc_drop(rqstp);
 	return 0;
 }