[NETFILTER]: conntrack: get rid of sparse warnings

Teach sparse about locking here, and fix signed/unsigned warnings.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 47d8947..775f7d4 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -28,7 +28,7 @@
 
 #define MAX_PORTS	8
 static unsigned short ports[MAX_PORTS];
-static int ports_c;
+static unsigned int ports_c;
 module_param_array(ports, ushort, &ports_c, 0400);
 MODULE_PARM_DESC(ports, "port numbers of SIP servers");
 
@@ -407,7 +407,7 @@
 	unsigned int dataoff, datalen;
 	const char *dptr;
 	int ret = NF_ACCEPT;
-	int matchoff, matchlen;
+	unsigned int matchoff, matchlen;
 	u_int16_t port;
 	enum sip_header_pos pos;
 	typeof(nf_nat_sip_hook) nf_nat_sip;