tipc: Improve handling of media address printing errors

Enhances conversion of a media address to printable form so that an
unconvertable address will be displayed as a string of hex digits,
rather than not being displayed at all. (Also removes a pointless check
for the existence of the media-specific address conversion routine,
since the routine is not optional.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 148ed04..4e9367f 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -83,8 +83,7 @@
 			struct tipc_media_addr *dest);
 	int (*enable_bearer)(struct tipc_bearer *b_ptr);
 	void (*disable_bearer)(struct tipc_bearer *b_ptr);
-	char *(*addr2str)(struct tipc_media_addr *a,
-			  char *str_buf, int str_size);
+	int (*addr2str)(struct tipc_media_addr *a, char *str_buf, int str_size);
 	struct tipc_media_addr bcast_addr;
 	u32 priority;
 	u32 tolerance;