xsk: Fix corrupted packets for XDP_SHARED_UMEM

In the Linux kernel, the following vulnerability has been resolved: xsk: Fix corrupted packets for XDP_SHARED_UMEM Fix an issue in XDP_SHARED_UMEM mode together with aligned mode where packets are corrupted for the second and any further sockets bound to the same umem. In other words, this does not affect the first socket bound to the umem. The culprit for this bug is that the initialization of the DMA addresses for the pre-populated xsk buffer pool entries was not performed for any socket but the first one bound to the umem. Only the linear array of DMA addresses was populated. Fix this by populating the DMA addresses in the xsk buffer pool for every socket bound to the same umem.