ipv6: bool/const conversions phase2

Mostly bool conversions, some inline removals and const additions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 1402139..aecf884 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -559,7 +559,7 @@
 extern int			ipv6_skip_exthdr(const struct sk_buff *, int start,
 					         u8 *nexthdrp, __be16 *frag_offp);
 
-extern int 			ipv6_ext_hdr(u8 nexthdr);
+extern bool			ipv6_ext_hdr(u8 nexthdr);
 
 extern int ipv6_find_tlv(struct sk_buff *skb, int offset, int type);