mysqld should auto-terminate when started with --wsrep-recover

There is a stage in mysqld_safe when it tries to recover mysqld's
database state by starting it with --wsrep-recover. The server is expected
to exit after recovery. After which, mysqld_safe attempts to start the server
again.

However, if server is started using mysqld_safe with wsrep disabled,
mysqld wouldn't terminate post recovery. Due to this init commands
like stop, start won't work as the pid file used to start mysql is different
from what init script expects.

  local wr_pidfile="$DATADIR/"`@HOSTNAME@`"-recover.pid"