RDMA/core: Correct format of block comments

Block comments should not use a trailing */ on a separate line and every
line of a block comment should start with an '*'.

Link: https://lore.kernel.org/r/1617783353-48249-7-git-send-email-liweihang@huawei.com
Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>