lpfc: Fix mbox reuse in PLOGI completion

lpfc: Fix mbox reuse in PLOGI completion

Fix mbox reuse in PLOGI completion. Moved allocations so that buffer
properly init'd.

Signed-off-by: Dick Kennedy <dick.kennedy@avagotech.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 01c73bbcd7cc4f31f45a1b0caeacdba46acd9c9c)

Orabug: 22493326

Signed-off-by: Manjunath Govindashetty <manjunath.govindashetty@oracle.com>