scsi: lpfc: Ensure PLOGI_ACC is sent prior to PRLI in Point to Point topology

There is a timing race condition when a PRLI may be sent on the wire
before PLOGI_ACC in Point to Point topology.  Fix by deferring REG_RPI
mbox completion handling to after PLOGI_ACC's CQE completion.  Because
the discovery state machine only sends PRLI after REG_RPI mbox
completion, PRLI is now guaranteed to be sent after PLOGI_ACC.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Message-ID: <20250915180811.137530-8-justintee8345@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>