[Fix] ivshmem does not support for interrupts when it is plain mode

[leiqi96]

[leiqi96]

if ivshmem type is plain mode ,it cannot register uio with some old linux version.

v2.6.32 uio_register_device() if (idev->info->irq >= 0) { ret = request_irq(idev->info->irq, uio_interrupt, idev->info->irq_flags, idev->info->name, idev); if (ret) goto err_request_irq; }

v3.17.8 uio_register_device() if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { ret = devm_request_irq(idev->dev, info->irq, uio_interrupt, info->irq_flags, info->name, idev); if (ret) goto err_request_irq; }