fs/ext4/ext4fs.c: Free dirnode in error path of ext4fs_ls

As reported by Coverity, we did not free dirnode in the case of failure.
Do so now.

Reported-by: Coverity (CID: 131221)
Cc: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Tom Rini <trini@konsulko.com>

fs/ext4/ext4fs.c

@@ -167,6 +167,7 @@ int ext4fs_ls(const char *dirname)
 				  FILETYPE_DIRECTORY);
 	if (status != 1) {
 		printf("** Can not find directory. **\n");
+		ext4fs_free_node(dirnode, &ext4fs_root->diropen);
 		return 1;
 	}