xfs: use vfs inode nlink field everywhere

The VFS tracks the inode nlink just like the xfs_icdinode. We can
remove the variable from the icdinode and use the VFS inode variable
everywhere, reducing the size of the xfs_icdinode by a further 4
bytes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 4b79cf0..611c25c 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -4337,7 +4337,7 @@
 	if (error)
 		goto fail_iput;
 
-	ASSERT(ip->i_d.di_nlink == 0);
+	ASSERT(VFS_I(ip)->i_nlink == 0);
 	ASSERT(ip->i_d.di_mode != 0);
 
 	/* setup for the next pass */