convert-chunks: Dynamically check if profiling is enabled
convert-chunks: Dynamically check if profiling is enabled

- Condition profiling on a global variable rather than a cpp macro

- Don't printf from profile signal handler; instead, have the handler set a
flag which causes a profile message after the next chunk completion

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr