IB/isert: Do not excplicitly check == false for bool

It is not the kernel style, warning reported by coccicheck:

./ib_isert.c:1104:12-24: WARNING: Comparison to bool

Link: https://lore.kernel.org/r/1604404674-32998-1-git-send-email-zou_wei@huawei.com


Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>