xfs: don't return EFSCORRUPTED when scrubbing corrupt parent pointers

xfs: don't return EFSCORRUPTED when scrubbing corrupt parent pointers

LOLLM noticed that scrub sets the CORRUPT flag when xfs_parent_from_attr
thinks it's been given a corrupt parent pointer.  This eliminates the
potential to repair the filesystem because that error code is bubbled up
the call stack.  Fix this by collapsing them all to ECANCELED in
xchk_parent_pptr, which doesn't have that trait.

Cc: stable@vger.kernel.org # v6.10
Fixes: 0d29a20fbdba89 ("xfs: scrub parent pointers")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>