Get rid of warnings when compiled with -Wformat-security

Change-Id: I0e2346dfaa92ce1a9bf2734f033b12a9b775c3d7
diff --git a/nettest_bsd.c b/nettest_bsd.c
index 27092f3..e726d30 100644
--- a/nettest_bsd.c
+++ b/nettest_bsd.c
@@ -1164,7 +1164,7 @@
   /* the headers. we know some of it here, but not all, so we will */
   /* only print the test title here and will print the results */
   /* titles after the test is finished */
-  fprintf(where,test_name);
+  fprintf(where, "%s", test_name);
   address_buf[0] = '\0';
   inet_ntop(source->ai_family,get_address_address(source),address_buf,sizeof(address_buf));
   fprintf(where,