virtio: fix typo in virtio_device_ready() comment
"coherenct" -> "coherent"
Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ")
Message-Id: <db286e9a65449347f6584e68c9960fd5ded2b4b0.1763026134.git.mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>