ib_srpt: fix a WARN_ON() message

The first argument of WARN_ON() is a condition, so it means the warning
message here will just be the name without the ->qp_num information.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>