The _remove operator isn't working correctly when used with a variable that
expands to several items, so add a test case to exercise this path.
(Bitbake rev: cb2a62a5fbffb358528a85b46c1fc6383286cb9d)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>