IB/iser: use true,false for bool variable

Fixes coccicheck warning:

drivers/infiniband/ulp/iser/iser_memory.c:530:2-21: WARNING: Assignment of 0/1 to bool variable
drivers/infiniband/ulp/iser/iser_verbs.c:1096:2-21: WARNING: Assignment of 0/1 to bool variable

Link: https://lore.kernel.org/r/1577176812-2238-4-git-send-email-zhengbin13@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>