blktrace support: fixups/cleanups/improvements

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fifo.c b/fifo.c
index 5406aa5..df165f7 100644
--- a/fifo.c
+++ b/fifo.c
@@ -35,7 +35,7 @@
 
 	fifo->buffer = malloc(size);
 	fifo->size = size;
-	fifo->in = fifo->out = 0xffff0000;
+	fifo->in = fifo->out = 0;
 
 	return fifo;
 }