[NETFILTER]: nf_conntrack: naming unification

Rename all "conntrack" variables to "ct" for more consistency and
avoiding some overly long lines.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c
index 7017b16..f9a0837 100644
--- a/net/netfilter/nf_conntrack_proto_sctp.c
+++ b/net/netfilter/nf_conntrack_proto_sctp.c
@@ -25,7 +25,7 @@
 #include <net/netfilter/nf_conntrack_l4proto.h>
 #include <net/netfilter/nf_conntrack_ecache.h>
 
-/* Protects conntrack->proto.sctp */
+/* Protects ct->proto.sctp */
 static DEFINE_RWLOCK(sctp_lock);
 
 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more