When I try to call function which_terminal() of utils.py directly,
it complains NameError: global name 'bb' is not defined
So import module bb
(Bitbake rev: 9e370d9b1022112be2ac8f73feb182b1bba179b0)
Signed-off-by: Kang Kai <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>