nat: sizeof char * != sizeof char[], make the code work on 64bit systems

The test cases were failing on 64bit systems because the sizeof
code operated on the pointer size which is 8 and longer than the
size that was intended to be used for comparing it.

debian/changelog

@@ -1,3 +1,9 @@
+openbsc (0.12.0+git26-7) unstable; urgency=low
+
+  * 64bit fix for the MGCP rewriting
+
+ -- Holger Hans Peter Freyther <holger@freyther.de>  Wed, 07 Nov 2012 11:39:34 +0100
+
 openbsc (0.12.0+git26-6) precise; urgency=low
 
   * Added init script for osmocom-sgsn. 

openbsc/src/osmo-bsc_nat/bsc_mgcp_utils.c

@@ -557,13 +557,13 @@ static void patch_mgcp(struct msgb *output, const char *op, const char *tok,
 /* we need to replace some strings... */
 struct msgb *bsc_mgcp_rewrite(char *input, int length, int endpoint, const char *ip, int port)
 {
-	static const char *crcx_str = "CRCX ";
-	static const char *dlcx_str = "DLCX ";
-	static const char *mdcx_str = "MDCX ";
+	static const char crcx_str[] = "CRCX ";
+	static const char dlcx_str[] = "DLCX ";
+	static const char mdcx_str[] = "MDCX ";
 
-	static const char *ip_str = "c=IN IP4 ";
-	static const char *aud_str = "m=audio ";
-	static const char *fmt_str = "a=fmtp: ";
+	static const char ip_str[] = "c=IN IP4 ";
+	static const char aud_str[] = "m=audio ";
+	static const char fmt_str[] = "a=fmtp:";
 
 	char buf[128];
 	char *running, *token;