Fix segfault when displaying usage for installed iphoneinfo and iphonesyslog

dev/syslog_relay.c

diff --git a/dev/syslog_relay.c b/dev/syslog_relay.c
index e552e9c..6698653 100644
--- a/dev/syslog_relay.c
+++ b/dev/syslog_relay.c
@@ -154,7 +154,10 @@
 
 void print_usage(int argc, char **argv)
 {
-	printf("Usage: %s [OPTIONS]\n", (strrchr(argv[0], '/') + 1));
+	char *name = NULL;
+	
+	name = strrchr(argv[0], '/');
+	printf("Usage: %s [OPTIONS]\n", (name ? name + 1: argv[0]));
 	printf("Relay syslog of a connected iPhone/iPod Touch.\n\n");
 	printf("  -d, --debug\t\tenable communication debugging\n");
 	printf("  -u, --uuid UUID\ttarget specific device by its 40-digit device UUID\n");