xfs: zero i_nlink before repair puts inode on unlinked list

xfs: zero i_nlink before repair puts inode on unlinked list

LOLLM observes that we don't reset i_nlink if we encounter a file with
no parent that isn't on the unlinked list.  This causes unnecessary
assertion trips on debugging kernels and an inconsistent file, so let's
fix that.

Cc: stable@vger.kernel.org # v6.10
Fixes: 669dfe883c8e20 ("xfs: update the unlinked list when repairing link counts")
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>