net: annotate inet_timewait_sock bitfields

The use of bitfields here would lead to false positive warnings with
kmemcheck. Silence them.

(Additionally, one erroneous comment related to the bitfield was also
fixed.)
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

include/net/inet_timewait_sock.h

@@ -16,6 +16,7 @@
 #define _INET_TIMEWAIT_SOCK_
 
 
+#include <linux/kmemcheck.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/timer.h>
@@ -127,10 +128,12 @@ struct inet_timewait_sock {
 	__be32			tw_rcv_saddr;
 	__be16			tw_dport;
 	__u16			tw_num;
+	kmemcheck_bitfield_begin(flags);
 	/* And these are ours. */
 	__u8			tw_ipv6only:1,
 				tw_transparent:1;
-	/* 15 bits hole, try to pack */
+	/* 14 bits hole, try to pack */
+	kmemcheck_bitfield_end(flags);
 	__u16			tw_ipv6_offset;
 	unsigned long		tw_ttd;
 	struct inet_bind_bucket	*tw_tb;

net/ipv4/inet_timewait_sock.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/kmemcheck.h>
 #include <net/inet_hashtables.h>
 #include <net/inet_timewait_sock.h>
 #include <net/ip.h>
@@ -117,6 +118,8 @@ struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int stat
 	if (tw != NULL) {
 		const struct inet_sock *inet = inet_sk(sk);
 
+		kmemcheck_annotate_bitfield(tw, flags);
+
 		/* Give us an identity. */
 		tw->tw_daddr	    = inet->daddr;
 		tw->tw_rcv_saddr    = inet->rcv_saddr;