[NET]: Add const markers to various variables.

the patch below marks various variables const in net/; the goal is to
move them to the .rodata section so that they can't false-share
cachelines with things that get written to, as well as potentially
helping gcc a bit with optimisations.  (these were found using a gcc
patch to warn about such variables)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipvs/ip_vs_conn.c b/net/ipv4/ipvs/ip_vs_conn.c
index f828fa2..2a3a8c5 100644
--- a/net/ipv4/ipvs/ip_vs_conn.c
+++ b/net/ipv4/ipvs/ip_vs_conn.c
@@ -771,7 +771,7 @@
 	 * The drop rate array needs tuning for real environments.
 	 * Called from timer bh only => no locking
 	 */
-	static char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
+	static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
 	static char todrop_counter[9] = {0};
 	int i;