RDMA/cxgb4: "cookie" can stay in host endianness

RDMA/cxgb4: "cookie" can stay in host endianness

Work requests are passed between the host and the firmware with a
"cookie".  This cookie is swapped to big-endian when passed to the
firmware and back to host endianness on return.  This swapping seems
to be implemented incorrectly.  Moreover, the byte swapping triggers
GCC warnings on 32 bit:

    drivers/infiniband/hw/cxgb4/cm.c: In function ‘passive_ofld_conn_reply’:
    drivers/infiniband/hw/cxgb4/cm.c:2803:12: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    drivers/infiniband/hw/cxgb4/cm.c: In function ‘send_fw_pass_open_req’:
    drivers/infiniband/hw/cxgb4/cm.c:2941:16: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    [...]

But byte swapping isn't needed as the firmware doesn't actually touch
the cookie.  Dropping byte swapping makes the warnings go away too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Roland Dreier <roland@purestorage.com>