scsi: fcoe: Embed fc_rport_priv in fcoe_rport structure

Gcc-9 complains for a memset across pointer boundaries, which happens as
the code tries to allocate a flexible array on the stack.  Turns out we
cannot do this without relying on gcc-isms, so with this patch we'll embed
the fc_rport_priv structure into fcoe_rport, can use the normal
'container_of' outcast, and will only have to do a memset over one
structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libfc/fc_rport.c

@@ -128,6 +128,7 @@ EXPORT_SYMBOL(fc_rport_lookup);
 struct fc_rport_priv *fc_rport_create(struct fc_lport *lport, u32 port_id)
 {
 	struct fc_rport_priv *rdata;
+	size_t rport_priv_size = sizeof(*rdata);
 
 	lockdep_assert_held(&lport->disc.disc_mutex);
 
@@ -135,7 +136,9 @@ struct fc_rport_priv *fc_rport_create(struct fc_lport *lport, u32 port_id)
 	if (rdata)
 		return rdata;
 
-	rdata = kzalloc(sizeof(*rdata) + lport->rport_priv_size, GFP_KERNEL);
+	if (lport->rport_priv_size > 0)
+		rport_priv_size = lport->rport_priv_size;
+	rdata = kzalloc(rport_priv_size, GFP_KERNEL);
 	if (!rdata)
 		return NULL;