svcrdma: Fix tracepoint printk format

Other tracepoints use "cq.id=" rather than "cq_id=". Let's make it
more reliable to grep for the CQ restracker ID.

Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>