iser-target: Cast wr_id with uintptr_t instead of unsinged long

Nit, uintptr_t is designed for pointer casting, use it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --cc drivers/infiniband/ulp/isert/ib_isert.c
Simple merge