cxgb4: fix SGE queue dump destination buffer context

The data in destination buffer is expected to be be parsed in big
endian. So, use the right context.

Fixes following sparse warning:
cudbg_lib.c:2041:44: warning: incorrect type in assignment (different
base types)
cudbg_lib.c:2041:44:    expected unsigned long long [usertype]
cudbg_lib.c:2041:44:    got restricted __be64 [usertype]

Fixes: 736c3b94

 ("cxgb4: collect egress and ingress SGE queue contexts")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>