[IPV6]: make extended headers to return an error at initialization

This patch factorize the code for the differents init functions for rthdr,
nodata, destopt in a single function exthdrs_init.
This function returns an error so the af_inet6 module can check correctly
the initialization.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/transp_v6.h b/include/net/transp_v6.h
index 409da3a..610b1bb7 100644
--- a/include/net/transp_v6.h
+++ b/include/net/transp_v6.h
@@ -17,10 +17,9 @@
 struct flowi;
 
 /* extention headers */
-extern void				ipv6_rthdr_init(void);
+extern int				ipv6_exthdrs_init(void);
+extern void				ipv6_exthdrs_exit(void);
 extern void				ipv6_frag_init(void);
-extern void				ipv6_nodata_init(void);
-extern void				ipv6_destopt_init(void);
 
 /* transport protocols */
 extern void				rawv6_init(void);