net: rename local_df to ignore_df

As suggested by several people, rename local_df to ignore_df,
since it means "ignore df bit if it is set".

Cc: Maciej Żenczykowski <maze@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 3ca0dda..7a9beeb 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -426,7 +426,7 @@
  *	@csum_start: Offset from skb->head where checksumming should start
  *	@csum_offset: Offset from csum_start where checksum should be stored
  *	@priority: Packet queueing priority
- *	@local_df: allow local fragmentation
+ *	@ignore_df: allow local fragmentation
  *	@cloned: Head may be cloned (check refcnt to be sure)
  *	@ip_summed: Driver fed us an IP checksum
  *	@nohdr: Payload reference only, must not modify header
@@ -514,7 +514,7 @@
 	};
 	__u32			priority;
 	kmemcheck_bitfield_begin(flags1);
-	__u8			local_df:1,
+	__u8			ignore_df:1,
 				cloned:1,
 				ip_summed:2,
 				nohdr:1,