The bit field rsvd1 in resp is not being initialized and garbage data is
being copied from the stack back to userspace via the ib_copy_to_udata
call. Fix this by setting the entire struct resp to zero; this will ensure
that further new bit fields in the future will be zero'd too.

Link: https://lore.kernel.org/r/20210623182437.163801-1-colin.king@canonical.com
Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 87974051 ("RDMA/bnxt_re: Update ABI to pass wqe-mode to user space")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
[jgg: remove extra zeroing]
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>