i40e: fix error return code in i40e_probe()

Fix to return -ENOMEM in the memory alloc error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <[e-mail]>
Tested-by: Kavindya Deegala <[e-mail]>
Signed-off-by: Jeff Kirsher <[e-mail]>

drivers/net/ethernet/intel/i40e/i40e_main.c

···
 	 */
 	len = sizeof(struct i40e_vsi *) * pf->hw.func_caps.num_vsis;
 	pf->vsi = kzalloc(len, GFP_KERNEL);
-	if (!pf->vsi)
+	if (!pf->vsi) {
+		err = -ENOMEM;
 		goto err_switch_setup;
+	}
 
 	err = i40e_setup_pf_switch(pf);
 	if (err) {