xfs_scrub: don't warn about zero width joiner control characters

xfs_scrub: don't warn about zero width joiner control characters

The Unicode code point for "zero width joiners" (aka 0x200D) is used to
hint to renderers that a sequence of simple code points should be
combined into a more complex rendering.  This is how compound emoji such
as "wounded heart" are composed out of "heart" and "bandaid"; and how
complex glyphs are rendered in Malayam.

Emoji in filenames are a supported usecase, so stop warning about the
mere existence of ZWJ.  We already warn about ZWJ that are used to
produce confusingly rendered names in a single namespace, so we're not
losing any robustness here.

Cc: <linux-xfs@vger.kernel.org> # v6.10.0
Fixes: d43362c78e3e37 ("xfs_scrub: store bad flags with the name entry")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>