drivers/net/wan: fix warning: format not a string literal and no ...

Impact: Use 'static const char[]' instead of 'static char[]'.

Fix this compilation warnings:
  drivers/net/wan/lapbether.c: In function 'lapbeth_init_driver':
  drivers/net/wan/lapbether.c:441: warning: format not a string literal and no format arguments
  drivers/net/wan/z85230.c: In function 'z85230_init_driver':
  drivers/net/wan/z85230.c:1782: warning: format not a string literal and no format arguments

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
index da9dcf5..06beba4 100644
--- a/drivers/net/wan/lapbether.c
+++ b/drivers/net/wan/lapbether.c
@@ -430,7 +430,8 @@
 	.notifier_call = lapbeth_device_event,
 };
 
-static char banner[] __initdata = KERN_INFO "LAPB Ethernet driver version 0.02\n";
+static const char banner[] __initdata =
+	KERN_INFO "LAPB Ethernet driver version 0.02\n";
 
 static int __init lapbeth_init_driver(void)
 {