scsi: lpfc: Protect vport fc_nodes list with an explicit spin lock

scsi: lpfc: Protect vport fc_nodes list with an explicit spin lock

In attempt to reduce the amount of unnecessary shost_lock acquisitions in
the lpfc driver, replace shost_lock with an explicit fc_nodes_list_lock
spinlock when accessing vport->fc_nodes lists.  Although vport memory
region is owned by shost->hostdata, it is driver private memory and an
explicit fc_nodes list lock for fc_nodes list mutations is more appropriate
than locking the entire shost.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240131185112.149731-14-justintee8345@gmail.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>