IB/rxe: Update caller's CRC for RXE_MEM_TYPE_DMA memory type

Callers of rxe_mem_copy() provide pointer to store updated CRC
value. That pointer was supposed to be updated, but the
commit cee2688e ("IB/rxe: Offload CRC calculation when possible")
mistakenly removed that assignment for RXE_MEM_TYPE_DMA memory type.

The code worked because there are no actual callers with
RXE_MEM_TYPE_DMA, who are interested in returned value of crcp.
The one caller in read_reply(), who uses the returned crcp didn't
set RXE_MEM_TYPE_DMA as mem->type.

Fixes: cee2688e ("IB/rxe: Offload CRC calculation when possible")
Reported-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Andrew Boyer <andrew.boyer@dell.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>