Initialize logmtx and watcher_cond before the first log rewrite

I had missed to move these when I changed the locking scheme
of rewrites before the public release, and I find it curious
that my test systems did not complain.

Anyway, fixes #1

src/fellow_log.c

@@ -5482,6 +5482,12 @@ fellow_logwatcher_init(struct fellow_fd *ffd)
 	AZ(pthread_condattr_init(&ca));
 	AZ(pthread_condattr_setclock(&ca, CLOCK_MONOTONIC));
 	AZ(pthread_cond_init(&ffd->watcher_cond, &ca));
+}
+
+// not unter logmtx
+static void
+fellow_logwatcher_start(struct fellow_fd *ffd)
+{
 	ffd->watcher_running = 1;
 	AZ(pthread_create(&ffd->watcher_thread, NULL,
 		fellow_logwatcher_thread, ffd));
@@ -5859,6 +5865,9 @@ fellow_log_open(struct fellow_fd *ffd,
 	struct fellow_log_memfail mf[1];
 	pthread_t mf_thread;
 
+	AZ(pthread_mutex_init(&ffd->logmtx, NULL));
+	fellow_logwatcher_init(ffd);
+
 	INIT_OBJ(mf, FELLOW_LOG_MEMFAIL_MAGIC);
 	mf->membuddy = ffd->membuddy;
 	mf->phase = 1;
@@ -5875,8 +5884,7 @@ fellow_log_open(struct fellow_fd *ffd,
 	}
 	AZ(pthread_join(mf_thread, NULL));
 
-	AZ(pthread_mutex_init(&ffd->logmtx, NULL));
-	fellow_logwatcher_init(ffd);
+	fellow_logwatcher_start(ffd);
 }
 
 void