net: fujitsu: fix a potential NULL pointer dereference

In case ioremap fails, the fix releases the pcmcia window and
returns -ENOMEM to avoid the NULL pointer dereference.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/fujitsu/fmvj18x_cs.c

@@ -547,6 +547,11 @@ static int fmvj18x_get_hwinfo(struct pcmcia_device *link, u_char *node_id)
 	return -1;
 
     base = ioremap(link->resource[2]->start, resource_size(link->resource[2]));
+    if (!base) {
+	    pcmcia_release_window(link, link->resource[2]);
+	    return -ENOMEM;
+    }
+
     pcmcia_map_mem_page(link, link->resource[2], 0);
 
     /*