Fixed race condition in the Restore workflow

When an instance is restored from a backup, during the step when the root
password is being reset, we now check to ensure that the mysqld daemon is
up, before we kill the process. This ensures that the root password is
always reset successfully.

Fixes bug 1187958

Change-Id: If5a5c0293c0dc51c3f118abbcc52c3fb0d1d3cfa