mgcp_test: do not send rtp packets

The sendto() override in mgcp_test sends rtp packets out. This
might be a problem for some test hosts. e.g. on OBS, sending packets
fails with an error message, which exits sendto() early and hence fails
to send the expected amount of "Dummy Packets". Interestingly enough
calling the real sendto is not necessary to run the test at all.

Remove the execution of the real_sendto and just return len.

Related: OS#2561
Change-Id: Ia8fa0770f9bc75725cc6b0cd445e753f7e029ca5
diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index 5b292a5..e14b7ee 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -509,16 +509,10 @@
 ssize_t sendto(int sockfd, const void *buf, size_t len, int flags,
 	       const struct sockaddr *dest_addr, socklen_t addrlen)
 {
-	typedef ssize_t(*sendto_t) (int, const void *, size_t, int,
-				    const struct sockaddr *, socklen_t);
-	static sendto_t real_sendto = NULL;
 	uint32_t dest_host =
 	    htonl(((struct sockaddr_in *)dest_addr)->sin_addr.s_addr);
 	int dest_port = htons(((struct sockaddr_in *)dest_addr)->sin_port);
 
-	if (!real_sendto)
-		real_sendto = dlsym(RTLD_NEXT, "sendto");
-
 	if (len == 1 && ((const char *)buf)[0] == MGCP_DUMMY_LOAD) {
 		fprintf(stderr,
 			"Dummy packet to 0x%08x:%d, msg length %zu\n%s\n\n",
@@ -526,7 +520,7 @@
 		dummy_packets += 1;
 	}
 
-	return real_sendto(sockfd, buf, len, flags, dest_addr, addrlen);
+	return len;
 }
 
 static int64_t force_monotonic_time_us = -1;