iser-target: Don't wait for session commands from completion context

Might result in a deadlock where completion context waits for
session commands release where the later might need a final
completion for 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