[mgcp] Fix format string usage
diff --git a/openbsc/src/mgcp/mgcp_main.c b/openbsc/src/mgcp/mgcp_main.c
index 147a765..6369fee 100644
--- a/openbsc/src/mgcp/mgcp_main.c
+++ b/openbsc/src/mgcp/mgcp_main.c
@@ -77,7 +77,7 @@
 static void print_version()
 {
 	printf("%s\n\n", openbsc_version);
-	printf(openbsc_copyright);
+	printf("%s", openbsc_copyright);
 }
 
 static void handle_options(int argc, char** argv)