hw/rdma: Cosmetic change - no need for two sge arrays

hw/rdma: Cosmetic change - no need for two sge arrays

The function build_host_sge_array uses two sge arrays, one for input and
one for output.
Since the size of the two arrays is the same, the function can write
directly to the given source array (i.e. input/output argument).

Signed-off-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Message-Id: <20200320143429.9490-2-yuval.shaia.ml@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>