When both bash and busybox be installed, without ash support
in busybox,if bash is installed before busybox in the final stage,
even if ALTERNATIVE_PRIORITY of bash > ALTERNATIVE_PRIORITY of busybox,
the symlink from /bin/sh to bash can be yet overwritten by busybox.
(From OE-Core rev: 6ef650359cc2a49376eb5ca92bc97b34cdd82862)
Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>