fs readdir: check for NULL pointer again

This got lost in:

commit 6188685091c58c9772b990cf0ca6ac522f97a9d0
Author: Sascha Hauer <s.hauer@pengutronix.de>
Date:   Sun May 13 12:43:58 2012 +0200

    Make errno a positive value

    Normally errno contains a positive error value. A certain unnamed developer
    mixed this up while implementing U-Boot-v2. Also, normally errno is never
    set to zero by any library function.
    This patch fixes this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/fs.c b/fs/fs.c
index ea5ed11587..e5ae6d532b 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -1077,6 +1077,9 @@ struct dirent *readdir(DIR *dir)
 {
 	struct dirent *ent;
 
+	if (!dir)
+		return NULL;
+
 	ent = dir->fsdrv->readdir(dir->dev, dir);
 
 	if (!ent)