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/ah6.c b/net/ipv6/ah6.c
index 5d32e7a..f1a4a2c 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -113,7 +113,7 @@
 			     __alignof__(struct scatterlist));
 }
 
-static int zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
+static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
 {
 	u8 *opt = (u8 *)opthdr;
 	int len = ipv6_optlen(opthdr);
@@ -145,10 +145,10 @@
 		len -= optlen;
 	}
 	if (len == 0)
-		return 1;
+		return true;
 
 bad:
-	return 0;
+	return false;
 }
 
 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)