migration/rdma: Silence qemu_rdma_register_and_get_keys()

migration/rdma: Silence qemu_rdma_register_and_get_keys()

Functions that use an Error **errp parameter to return errors should
not also report them to the user, because reporting is the caller's
job.  When the caller does, the error is reported twice.  When it
doesn't (because it recovered from the error), there is no error to
report, i.e. the report is bogus.

qemu_rdma_write_one() violates this principle: it reports errors to
stderr via qemu_rdma_register_and_get_keys().  I elected not to
investigate how callers handle the error, i.e. precise impact is not
known.

Clean this up: silence qemu_rdma_register_and_get_keys().  I believe
the caller's error reports suffice.  If they don't, we need to convert
to Error instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20230928132019.2544702-51-armbru@redhat.com>