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/z85230.c b/drivers/net/wan/z85230.c
index 3d00971..ad4e79c 100644
--- a/drivers/net/wan/z85230.c
+++ b/drivers/net/wan/z85230.c
@@ -1775,7 +1775,8 @@
 /*
  *	Module support
  */
-static char banner[] __initdata = KERN_INFO "Generic Z85C30/Z85230 interface driver v0.02\n";
+static const char banner[] __initdata =
+	KERN_INFO "Generic Z85C30/Z85230 interface driver v0.02\n";
 
 static int __init z85230_init_driver(void)
 {