MINOR: trace: make trace sources read_mostly
The trace sources are checked at plenty of places in the code and their
contents only change when trace status changes, let's mark them read_mostly.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index 5b23a29..aa885b8 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -244,7 +244,7 @@
{ /* end */ }
};
-static struct trace_source trace_h1 = {
+static struct trace_source trace_h1 __read_mostly = {
.name = IST("h1"),
.desc = "HTTP/1 multiplexer",
.arg_def = TRC_ARG1_CONN, // TRACE()'s first argument is always a connection