rdma/cxgb4: fix some info leaks

In c4iw_create_qp() there are several struct members which potentially
aren't inintialized like uresp.rq_key.  I've fixed this code before in
in commit ae1fe07f ("RDMA/cxgb4: Fix stack info leak in
c4iw_create_qp()") so this time I'm just going to take a big hammer
approach and memset the whole struct to zero.  Hopefully, it will stay
fixed this time.

In c4iw_create_srq() we don't clear uresp.reserved.

Fixes: 6a0b6174 ("rdma/cxgb4: Add support for kernel mode SRQ's")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>