scsi: lpfc: Avoid potential ndlp use-after-free in dev_loss_tmo_callbk

In the Linux kernel, the following vulnerability has been resolved:

scsi: lpfc: Avoid potential ndlp use-after-free in dev_loss_tmo_callbk

Smatch detected a potential use-after-free of an ndlp oject in dev_loss_tmo_callbk during driver unload or fatal error handling.

Fix by reordering code to avoid potential use-after-free if initial nodelist reference has been previously removed.