conf_func: Mark const and static.

const saves RAM, and static avoids namespace pollution.
diff --git a/firmware/src_simtrace/main.c b/firmware/src_simtrace/main.c
index debfb29..1454e02 100644
--- a/firmware/src_simtrace/main.c
+++ b/firmware/src_simtrace/main.c
@@ -19,7 +19,7 @@
     void (* run) ( void );
 } conf_func;
 
-conf_func config_func_ptrs[] = {
+static const conf_func config_func_ptrs[] = {
 	/* array slot 0 is empty, usb configs start at 1 */
 	[CFG_NUM_SNIFF] = {
 		.configure = Sniffer_configure,