init-live.sh: move /media/xxx over to the real root filesystem

init-live.sh: move /media/xxx over to the real root filesystem

Previously, the /media/xxx which contains the root image was not
moved to be under the real root filesystem. Because of this, the
output of the 'mount' command is somewhat confusing, that is, it
has some mount point that is not even in the filesystem.

Besides, on some machine, it caused the recovery procedure when we
booted it next time.

This patches fixes this issue by moving the /media/xxx over to be
under the real root filesystem.

[YOCTO #2064]
[YOCTO #3705]

(From OE-Core rev: 261d21d36298bb7822ee7370c30441f42ef2b093)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>