RDMA/pvrdma: Replace spin_lock_irqsave with spin_lock in hard IRQ

There is no need to do irqsave and irqrestore in context of hard IRQ.

Link: https://lore.kernel.org/r/1612514278-49220-1-git-send-email-liweihang@huawei.com


Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>