ksmbd: fix possible refcount leak in smb2_open()

Reference count of acls will leak when memory allocation fails. Fix this
by adding the missing posix_acl_release().

Fixes: e2f34481 ("cifsd: add server-side procedures for SMB3")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/smb2pdu.c

@@ -2977,8 +2977,11 @@ int smb2_open(struct ksmbd_work *work)
 							sizeof(struct smb_acl) +
 							sizeof(struct smb_ace) * ace_num * 2,
 							GFP_KERNEL);
-					if (!pntsd)
+					if (!pntsd) {
+						posix_acl_release(fattr.cf_acls);
+						posix_acl_release(fattr.cf_dacls);
 						goto err_out;
+					}
 
 					rc = build_sec_desc(idmap,
 							    pntsd, NULL, 0,