These two structures were used as the request and reply for certain
ioctls. Having a different type for an ioctl's input and output is
just wierd. In addition, each structure contained fields (e.g., pid)
that had no business being there.
This change requires updates to user-space.
This function used to return 'void *', which was then cast to
'xgi_pcie_block_t *' at the only caller. I changed the return type to
'struct xgi_pcie_block_s *' and removed the explicit cast.
