ocfs2: validate inline xattr header before checking outside values

ocfs2: validate inline xattr header before checking outside values

[BUG]
A corrupt inline xattr header can make
ocfs2_has_inline_xattr_value_outside() walk xh_count from an unchecked
header while refcount-tree teardown decides whether inline xattrs still
point outside the inode body.

[CAUSE]
ocfs2_has_inline_xattr_value_outside() still computed the inline header
directly from di->i_xattr_inline_size and immediately iterated xh_count.
That is the same unchecked metadata boundary as the ibody lookup bug.

[FIX]
Reuse the shared inline-header helper before iterating xh_count. Because
this helper returns a boolean-style answer to its caller, treat a corrupt
header conservatively as "has outside values" instead of walking it.

Link: https://lore.kernel.org/20260508085914.61647-3-gality369@gmail.com
Signed-off-by: ZhengYuan Huang <gality369@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Zixuan Fu <r33s3n6@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>