[SCSI] cxgb3i: check for setup netdev

If the netdev has not been setup when the host is, we will oops when
the iscsi layer calls into the driver and a it tries to reference the
netdev in hba->ndev.

This can happen if the iscsi driver is loaded before ifup is
done. This patch just adds a check, so we can gracefully fail the
operation.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/cxgb3i/cxgb3i_iscsi.c

@@ -708,6 +708,12 @@ static int cxgb3i_host_set_param(struct Scsi_Host *shost,
 {
 	struct cxgb3i_hba *hba = iscsi_host_priv(shost);
 
+	if (!hba->ndev) {
+		shost_printk(KERN_ERR, shost, "Could not set host param. "
+			     "Netdev for host not set.\n");
+		return -ENODEV;
+	}
+
 	cxgb3i_api_debug("param %d, buf %s.\n", param, buf);
 
 	switch (param) {
@@ -738,6 +744,12 @@ static int cxgb3i_host_get_param(struct Scsi_Host *shost,
 	struct cxgb3i_hba *hba = iscsi_host_priv(shost);
 	int len = 0;
 
+	if (!hba->ndev) {
+		shost_printk(KERN_ERR, shost, "Could not set host param. "
+			     "Netdev for host not set.\n");
+		return -ENODEV;
+	}
+
 	cxgb3i_api_debug("hba %s, param %d.\n", hba->ndev->name, param);
 
 	switch (param) {