xfs_scrub: store bad flags with the name entry

xfs_scrub: store bad flags with the name entry

When scrub is checking unicode names, there are certain properties of
the directory/attribute/label name itself that it can complain about.
Store these in struct name_entry so that the confusable names detector
can pick this up later.

This restructuring enables a subsequent patch to detect suspicious
sequences in the NFC normalized form of the name without needing to hang
on to that NFC form until the end of processing.  IOWs, it's a memory
usage optimization.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>