IB/isert: remove the handling of last WQE reached event

This event is raised for QPs that are associated with a Shared RQ (SRQ).
The iSER target does not support SRQ. Remove this dead code.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Link: https://lore.kernel.org/r/20240619171153.34631-3-mgurtovoy@nvidia.com


Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>