This patch is to fix the following:
if foo != None -----> if foo
if foo == None -----> if not foo
(From Poky rev: d771343b1726f166ed8d75543ba68bd2a20aee7b)
(Bitbake rev: 23c140a4d00293d922cbd34b6b837493cac2e93a)
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>