vdpa: Fix a couple of spelling mistakes in some messages

There are two spelling mistakes in some literal strings. Fix them.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Message-Id: <20230130092644.37002-1-colin.i.king@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>