This function can miss packages whose license is in
"COPYLEFT_LICENSE_EXCLUDE" and tarball packages with license in
"COPYLEFT_LICENSE_INCLUDE".
[YOCTO #2473]
(From OE-Core rev: 4800bed394ebd7fb50552a96d6a5f83d98fe790f)
Signed-off-by: Xiaofeng Yan <xiaofeng.yan@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>