ringbuf: fix cleanup operations

src/lxc/ringbuf.c

@@ -20,9 +20,9 @@
 
 int lxc_ringbuf_create(struct lxc_ringbuf *buf, size_t size)
 {
+	__do_close int memfd = -EBADF;
 	char *tmp;
 	int ret;
-	int memfd = -1;
 
 	buf->size = size;
 	buf->r_off = 0;
@@ -63,14 +63,10 @@ int lxc_ringbuf_create(struct lxc_ringbuf *buf, size_t size)
 	if (tmp == MAP_FAILED || tmp != (buf->addr + buf->size))
 		goto on_error;
 
-	close(memfd);
-
 	return 0;
 
 on_error:
 	lxc_ringbuf_release(buf);
-	if (memfd >= 0)
-		close(memfd);
 	return -1;
 }
 

src/lxc/ringbuf.h

@@ -36,7 +36,8 @@ extern int lxc_ringbuf_read(struct lxc_ringbuf *buf, char *out, size_t *len);
 
 static inline void lxc_ringbuf_release(struct lxc_ringbuf *buf)
 {
-	munmap(buf->addr, buf->size * 2);
+	if (buf->addr)
+		munmap(buf->addr, buf->size * 2);
 }
 
 static inline void lxc_ringbuf_clear(struct lxc_ringbuf *buf)