Fix fifo leak

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fifo.h b/fifo.h
index 6a9115d..cfacea9 100644
--- a/fifo.h
+++ b/fifo.h
@@ -28,6 +28,7 @@
 struct fifo *fifo_alloc(unsigned int);
 unsigned int fifo_put(struct fifo *, void *, unsigned int);
 unsigned int fifo_get(struct fifo *, void *, unsigned int);
+void fifo_free(struct fifo *);
 
 static inline unsigned int fifo_len(struct fifo *fifo)
 {