netsplice: fix a few typos

It actually works now.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/engines/net.c b/engines/net.c
index 4936cc2..a67432b 100644
--- a/engines/net.c
+++ b/engines/net.c
@@ -63,7 +63,7 @@
 	int bytes = 0;
 
 	while (len) {
-		int ret = splice(nd->pipes[1], NULL, f->fd, NULL, len, 0);
+		int ret = splice(f->fd, NULL, nd->pipes[1], NULL, len, 0);
 
 		if (ret < 0) {
 			if (!bytes)
@@ -74,6 +74,7 @@
 			break;
 
 		bytes += ret;
+		len -= ret;
 	}
 
 	return bytes;
@@ -131,6 +132,7 @@
 			break;
 
 		iov.iov_len -= ret;
+		bytes += ret;
 		if (iov.iov_len)
 			iov.iov_base += ret;
 	}