Use empty()

Author: peterschrammel

src/analyses/goto_check.cpp

@@ -1703,7 +1703,7 @@ void goto_checkt::goto_check(
         if(!it->source_location.get_column().empty())
           i_it->source_location.set_column(it->source_location.get_column());
 
-        if(it->source_location.get_java_bytecode_index()!=irep_idt())
+        if(!it->source_location.get_java_bytecode_index().empty())
           i_it->source_location.set_java_bytecode_index(
             it->source_location.get_java_bytecode_index());
       }