testutils: call va_end before return

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

tests/testutils.c

@@ -771,6 +771,7 @@ int virTestMain(int argc,
     while ((lib = va_arg(ap, const char *))) {
         if (!virFileIsExecutable(lib)) {
             perror(lib);
+            va_end(ap);
             return EXIT_FAILURE;
         }