net: move random_port() to dns

The random_port() routine is not used anywhere else. Make it local to
dns.c to reduce code clutter, and shrink generated code a little.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>

include/net.h

@@ -897,9 +897,6 @@ int is_serverip_in_cmd(void);
  */
 int net_parse_bootfile(struct in_addr *ipaddr, char *filename, int max_len);
 
-/* get a random source port */
-unsigned int random_port(void);
-
 /**
  * update_tftp - Update firmware over TFTP (via DFU)
  *

net/dns.c

@@ -36,6 +36,16 @@ char *net_dns_env_var;	/* The envvar to store the answer in */
 
 static int dns_our_port;
 
+/*
+ * make port a little random (1024-17407)
+ * This keeps the math somewhat trivial to compute, and seems to work with
+ * all supported protocols/clients/servers
+ */
+static unsigned int random_port(void)
+{
+	return 1024 + (get_timer(0) % 0x4000);
+}
+
 static void dns_send(void)
 {
 	struct header *header;

net/net.c

@@ -1564,20 +1564,6 @@ int net_parse_bootfile(struct in_addr *ipaddr, char *filename, int max_len)
 	return 1;
 }
 
-#if	defined(CONFIG_CMD_NFS)		|| \
-	defined(CONFIG_CMD_SNTP)	|| \
-	defined(CONFIG_CMD_DNS)
-/*
- * make port a little random (1024-17407)
- * This keeps the math somewhat trivial to compute, and seems to work with
- * all supported protocols/clients/servers
- */
-unsigned int random_port(void)
-{
-	return 1024 + (get_timer(0) % 0x4000);
-}
-#endif
-
 void ip_to_string(struct in_addr x, char *s)
 {
 	x.s_addr = ntohl(x.s_addr);