xfs: check xfarray iteration errors when committing unlinked inode lists

xfs: check xfarray iteration errors when committing unlinked inode lists

LOLLM noticed that we neglect to check for xfarray_iter itself returning
errors when writing a new AGI.  Fix that.

Cc: stable@vger.kernel.org # v6.10
Fixes: ab97f4b1c03075 ("xfs: repair AGI unlinked inode bucket lists")
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>