1. Extend the regular expression to also catch '^WARNING:' in _log_check_warn.
Warnings from bb.note or bbnote begin with 'WARNING:'. So if we decide to
catch warnings at rootfs time, we should not ignore those produced by
the build system itself.
2. Delay _log_check in rootfs process so that more warnings are likely to be
catched. Note that we should at least delay the _log_check after the
execution of ROOTFS_POSTPROCESS_COMMANDS, because we want to catch warnings
there.
Signed-off-by: Chen Qi <Qi.Chen@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
