Fix const warning

src/generator.c

@@ -792,7 +792,8 @@ static bool parse_notify(ckpool_t *ckp, proxy_instance_t *proxi, json_t *val)
 	const char *prev_hash, *bbversion, *nbit, *ntime;
 	proxy_instance_t *proxy = proxi->parent;
 	gdata_t *gdata = proxi->ckp->data;
-	char *coinbase1, *coinbase2, *buf;
+	char *coinbase1, *coinbase2;
+	const char *jobidbuf;
 	bool clean, ret = false;
 	notify_instance_t *ni;
 	json_t *arr, *job_id;
@@ -824,8 +825,8 @@ static bool parse_notify(ckpool_t *ckp, proxy_instance_t *proxi, json_t *val)
 	LOGDEBUG("Received new notify from proxy %d:%d", proxi->id, proxi->subid);
 	ni = ckzalloc(sizeof(notify_instance_t));
 	ni->jobid = job_id;
-	buf = json_string_value(job_id);
-	LOGDEBUG("JobID %s", buf);
+	jobidbuf = json_string_value(job_id);
+	LOGDEBUG("JobID %s", jobidbuf);
 	ni->coinbase1 = coinbase1;
 	LOGDEBUG("Coinbase1 %s", coinbase1);
 	ni->coinb1len = strlen(coinbase1) / 2;