xfs: centralize error tag definitions

Right now 5 places in the kernel and one in xfsprogs need to be updated
for each new error tag.  Add a bit of macro magic so that only the
error tag definition and a single table, which reside next to each
other, need to be updated.

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