IB/core: Fix bit curruption in ib_device_cap_flags structure

ib_device_cap_flags 64-bit expansion caused caps overlapping
and made consumers read wrong device capabilities. For example
IB_DEVICE_SG_GAPS_REG was falsely read by the iser driver causing
it to use a non-existing capability. This happened because signed
int becomes sign extended when converted it to u64. Fix this by
casting IB_DEVICE_ON_DEMAND_PAGING enumeration to ULL.

Fixes: f5aa9159

 ('IB/core: Add arbitrary sg_list support')
Reported-by: Robert LeBlanc <robert@leblancnet.us>
Cc: Stable <stable@vger.kernel.org> #[v4.6+]
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>