IB/counters: Always initialize the port counter object

IB/counters: Always initialize the port counter object

Port counter objects should be initialized even if alloc_stats is
unsupported, otherwise QP bind operations in user space can trigger a NULL
pointer deference if they try to bind QP on RDMA device which doesn't
support counters.

Fixes: 25a81ca9f9dd ("RDMA/core: Get sum value of all counters when perform a sysfs stat read")
Link: https://lore.kernel.org/r/20190723065733.4899-11-leon@kernel.org
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>