Fixes for some of clang scan-build detected issues

backends/jny/jny.cc

@@ -546,8 +546,9 @@ struct JnyPass : public Pass {
 
         std::ostream *f;
         std::stringstream buf;
+        bool empty = filename.empty();
 
-        if (!filename.empty()) {
+        if (!empty) {
             rewrite_filename(filename);
             std::ofstream *ff = new std::ofstream;
             ff->open(filename.c_str(), std::ofstream::trunc);
@@ -565,7 +566,7 @@ struct JnyPass : public Pass {
         JnyWriter jny_writer(*f, false, connections, attributes, properties);
         jny_writer.write_metadata(design, 0, invk.str());
 
-        if (!filename.empty()) {
+        if (!empty) {
             delete f;
         } else {
             log("%s", buf.str().c_str());