song_update, udp_server: workarounds for gcc 4.1 warnings

Annoying false positives.

src/song_update.c

@@ -113,6 +113,11 @@ song_file_update(struct song *song)
 
 	GMutex *mutex = NULL;
 	GCond *cond;
+#if !GCC_CHECK_VERSION(4, 2)
+	/* work around "may be used uninitialized in this function"
+	   false positive */
+	cond = NULL;
+#endif
 
 	do {
 		/* load file tag */

src/udp_server.c

@@ -97,6 +97,9 @@ udp_server_new(unsigned port,
 			.s_addr = htonl(INADDR_ANY),
 		},
 		.sin_port = htons(port),
+#if defined(__linux__) && !GCC_CHECK_VERSION(4, 2)
+		.sin_zero = { 0 },
+#endif
 	};
 
 	if (bind(fd, (const struct sockaddr *)&address, sizeof(address)) < 0) {