message: fix instructions in sampler.py
diff: #!/usr/bin/python2
  # run openocd (0.9.0) with :
  -# $ openocd -f stlink-v2-1.cfg -f stm32f4x.cfg &> /dev/null"
  +# $ openocd -f interface/stlink-v2.cfg -f target/stm32f4x.cfg &> /dev/null &
  # then run
  # $ python2 sampler.py path_to_myelf_with_symbols
  +# ctrl-c to stop sampling.
  +# To terminate the openocd session, enter command "fg" then do ctrl-c.
  import sys
  import time
  @@ -111,10 +113,10 @@ if __name__ == '__main__':
  cur = time.time()
  if cur - start > 1.0:
  - tmp = sorted(countmap.items(), key=operator.itemgetter(1), reverse=True)
  + tmp = sorted(countmap.items(), key=operator.itemgetter(1)) #, reverse=True)
  for k, v in tmp:
  - # print('{:05.2f}% {}'.format((v * 100.) / total, k))
  - print('{:06.2f} clocks : {}'.format((v * 8192) / total, k))
  + print('{:05.2f}% {}'.format((v * 100.) / total, k))
  + # print('{:06.2f} clocks : {}'.format((v * 10500) / total, k))
  start = cur
  print('{} Samples'.format(total))
  print('')
  