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/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 7b1a884..f73d59a 100644
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -9,7 +9,7 @@
  * find out if nexthdr is a well-known extension header or a protocol
  */
 
-int ipv6_ext_hdr(u8 nexthdr)
+bool ipv6_ext_hdr(u8 nexthdr)
 {
 	/*
 	 * find out if nexthdr is an extension header or a protocol