The attribute isn't used since commit 5c973678
"i82378: Cleanup implementation".

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20230523195608.125820-4-shentey@gmail.com>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>