RDMA/rtrs: Do not signal for heatbeat

For HB, there is no need to generate signal for completion.

Also remove a comment accordingly.

Fixes: c0894b3e ("RDMA/rtrs: core: lib functions shared between client and server modules")
Link: https://lore.kernel.org/r/20201217141915.56989-16-jinpu.wang@cloud.ionos.com


Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reported-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>