- darwin link fix

lib/cds/simple_profile.c

@@ -13,7 +13,7 @@ typedef void (*_sig_t) (int);
 
 unsigned int tick_counter = 0;
 static struct sigaction old_sigprof_action;
-_sig_t old_sigx_action;
+static _sig_t old_sigx_action;
 static int initialized = 0;
 static trace_f trace_function = NULL;