fs/squashfs: sqfs_read_inode_table: fix dangling pointer

inode_table should not be left dangling as it may be freed in sqfs_opendir
Signed-off-by: Richard Genoud <richard.genoud@posteo.net>

fs/squashfs/sqfs.c

@@ -731,6 +731,7 @@ static int sqfs_read_inode_table(unsigned char **inode_table)
 					      src_table, src_len);
 			if (ret) {
 				free(*inode_table);
+				*inode_table = NULL;
 				goto free_itb;
 			}