RDS: avoid duplicate connection drop for self loopback

RDS: avoid duplicate connection drop for self loopback

For self-IB loopback is special mode and the c_passive conn is just a
place holder to stick the the second QP.

Orabug: 22347191

Tested-by: Michael Nowak <michael.nowak@oracle.com>
Tested-by: Rafael Alejandro Peralez <rafael.peralez@oracle.com>
Tested-by: Liwen Huang <liwen.huang@oracle.com>
Tested-by: Hong Liu <hong.x.liu@oracle.com>
Reviewed-by: Mukesh Kacker <mukesh.kacker@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>