net: Convert SEQ_START_TOKEN/seq_printf to seq_puts

Using a single fixed string is smaller code size than using
a format and many string arguments.

Reduces overall code size a little.

$ size net/ipv4/igmp.o* net/ipv6/mcast.o* net/ipv6/ip6_flowlabel.o*
   text	   data	    bss	    dec	    hex	filename
  34269	   7012	  14824	  56105	   db29	net/ipv4/igmp.o.new
  34315	   7012	  14824	  56151	   db57	net/ipv4/igmp.o.old
  30078	   7869	  13200	  51147	   c7cb	net/ipv6/mcast.o.new
  30105	   7869	  13200	  51174	   c7e6	net/ipv6/mcast.o.old
  11434	   3748	   8580	  23762	   5cd2	net/ipv6/ip6_flowlabel.o.new
  11491	   3748	   8580	  23819	   5d0b	net/ipv6/ip6_flowlabel.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index c143437..7221021 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -770,8 +770,7 @@
 {
 	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 	if (v == SEQ_START_TOKEN) {
-		seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
-			   "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
+		seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 	} else {
 		struct ip6_flowlabel *fl = v;
 		seq_printf(seq,