IB: Fix information leak in marshalling code

ib_ucm_init_qp_attr() and ucma_init_qp_attr() pass struct ib_uverbs_qp_attr
with reserved, qp_state, {ah_attr,alt_ah_attr}{reserved,->grh.reserved}
fields uninitialized to copy_to_user().  This leads to leaking of
contents of kernel stack memory to userspace.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>