fs: ocfs2: namei: check return value of ocfs2_add_entry()

Process result of ocfs2_add_entry() in case we have an error
value.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://lkml.kernel.org/r/20230803145417.177649-1-artem.chernyshev@red-soft.ru
Fixes: ccd979bd

 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Kurt Hackel <kurt.hackel@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>