ratelim.h: use COCCI to hide an initializer.

src/lib/log/ratelim.h

@@ -45,7 +45,9 @@ typedef struct ratelim_t {
   int n_calls_since_last_time;
 } ratelim_t;
 
+#ifndef COCCI
 #define RATELIM_INIT(r) { (r), 0, 0 }
+#endif
 #define RATELIM_TOOMANY (16*1000*1000)
 
 char *rate_limit_log(ratelim_t *lim, time_t now);