fs: ext4: free directory node in ext4fs_exists()

The directory retrieved in ext4fs_exists() should be freed to avoid a
memory leak.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c
index 15587e9..2171414 100644
--- a/fs/ext4/ext4fs.c
+++ b/fs/ext4/ext4fs.c
@@ -209,12 +209,17 @@
 {
 	struct ext2fs_node *dirnode = NULL;
 	int filetype;
+	int ret;
 
 	if (!filename)
 		return 0;
 
-	return ext4fs_find_file1(filename, &ext4fs_root->diropen, &dirnode,
-				 &filetype);
+	ret = ext4fs_find_file1(filename, &ext4fs_root->diropen, &dirnode,
+				&filetype);
+	if (dirnode)
+		ext4fs_free_node(dirnode, &ext4fs_root->diropen);
+
+	return ret;
 }
 
 int ext4fs_size(const char *filename, loff_t *size)