debug: ensure that __dprint() is also logged over the network

We force local logging now, but that's not terribly useful
if you can't see the output from the backend. Make it follow
the usual rules of logging over the network if a backend, to
syslog, or locally.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/log.c b/log.c
index 4822c33..a05a7ec 100644
--- a/log.c
+++ b/log.c
@@ -14,6 +14,8 @@
 	len = vsnprintf(buffer, sizeof(buffer), str, args);
 	len = min(len, sizeof(buffer) - 1);
 
+	if (is_backend)
+		len = fio_server_text_output(FIO_LOG_INFO, buffer, len);
 	if (log_syslog)
 		syslog(LOG_INFO, "%s", buffer);
 	else