CVE-2021-47105

In the Linux kernel, the following vulnerability has been resolved: ice:
xsk: return xsk buffers back to pool when cleaning the ring Currently we
only NULL the xdp_buff pointer in the internal SW ring but we never give it
back to the xsk buffer pool. This means that buffers can be leaked out of
the buff pool and never be used again. Add missing xsk_buff_free() call to
the routine that is supposed to clean the entries that are left in the ring
so that these buffers in the umem can be used by other sockets. Also, only
go through the space that is actually left to be cleaned instead of a whole
ring.