[NETFILTER]: conntrack: add sysctl to disable checksumming

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 916013c..dbe7a11 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -285,6 +285,7 @@
 }
 
 extern unsigned int nf_conntrack_htable_size;
+extern int nf_conntrack_checksum;
 
 #define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)