[AX.25]: Fix default address and broadcast address initialization.

Only the callsign but not the SSID part of an AX.25 address is ASCII
based but Linux by initializes the SSID which should be just a 4-bit
number from ASCII anyway.

Fix that and convert the code to use a shared constant for both default
addresses.  While at it, use the same style for null_ax25_address also.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ax25.h b/include/net/ax25.h
index 41acb09..e1d116f 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -282,9 +282,9 @@
 extern struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
 
 /* ax25_addr.c */
-extern ax25_address null_ax25_address;
-extern char *ax2asc(char *buf, const ax25_address *);
-extern void asc2ax(ax25_address *addr, const char *callsign);
+extern const ax25_address ax25_bcast;
+extern const ax25_address ax25_defaddr;
+extern const ax25_address null_ax25_address;
 extern int ax25cmp(const ax25_address *, const ax25_address *);
 extern int ax25digicmp(const ax25_digi *, const ax25_digi *);
 extern const unsigned char *ax25_addr_parse(const unsigned char *, int,