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

Impact: Use 'static const char[]' instead of 'static char[]' and while
being at it fix an issue in 'mkiss_init_driver', where in case of an
error the status code was not passed to printk.

Fix this warnings:
  drivers/net/hamradio/6pack.c: In function 'sixpack_init_driver':
  drivers/net/hamradio/6pack.c:802: warning: format not a string literal and no format arguments
  drivers/net/hamradio/bpqether.c: In function 'bpq_init_driver':
  drivers/net/hamradio/bpqether.c:609: warning: format not a string literal and no format arguments
  drivers/net/hamradio/mkiss.c: In function 'mkiss_init_driver':
  drivers/net/hamradio/mkiss.c:988: warning: format not a string literal and no format arguments
  drivers/net/hamradio/mkiss.c:991: warning: format not a string literal and no format arguments
  drivers/net/hamradio/scc.c: In function 'scc_init_driver':
  drivers/net/hamradio/scc.c:2109: warning: format not a string literal and no format arguments
  drivers/net/hamradio/yam.c: In function 'yam_init_driver':
  drivers/net/hamradio/yam.c:1094: 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/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index ed5b37d..032c0db 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -976,9 +976,9 @@
 	.write_wakeup	= mkiss_write_wakeup
 };
 
-static char banner[] __initdata = KERN_INFO \
+static const char banner[] __initdata = KERN_INFO \
 	"mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n";
-static char msg_regfail[] __initdata = KERN_ERR \
+static const char msg_regfail[] __initdata = KERN_ERR \
 	"mkiss: can't register line discipline (err = %d)\n";
 
 static int __init mkiss_init_driver(void)
@@ -987,8 +987,9 @@
 
 	printk(banner);
 
-	if ((status = tty_register_ldisc(N_AX25, &ax_ldisc)) != 0)
-		printk(msg_regfail);
+	status = tty_register_ldisc(N_AX25, &ax_ldisc);
+	if (status != 0)
+		printk(msg_regfail, status);
 
 	return status;
 }