Log messages from shell-scripts were put to var/log/<test id>.log
file. Now, this file is used by mysql-test-run.pl. So, move log
messages to var/log/<test id>.script.log.


mysql-test/t/kill_n_check.sh:
  Log messages from shell-scripts were put to var/log/<test id>.log
  file. Now, this file is used by mysql-test-run.pl. So, move log
  messages to var/log/<test id>.script.log.
mysql-test/t/log.sh:
  Log messages from shell-scripts were put to var/log/<test id>.log
  file. Now, this file is used by mysql-test-run.pl. So, move log
  messages to var/log/<test id>.script.log.
mysql-test/t/wait_for_process.sh:
  Log messages from shell-scripts were put to var/log/<test id>.log
  file. Now, this file is used by mysql-test-run.pl. So, move log
  messages to var/log/<test id>.script.log.
mysql-test/t/wait_for_socket.sh:
  Log messages from shell-scripts were put to var/log/<test id>.log
  file. Now, this file is used by mysql-test-run.pl. So, move log
  messages to var/log/<test id>.script.log.