As the error is changed to warning, Trim.py will skip the build error when the source code have exactly issue. This patch change warning to error to opens the checking. Cc: Rebecca Cran <rebecca@bsdio.com> Cc: Liming Gao <gaoliming@byosoft.com.cn> Cc: Bob Feng <bob.c.feng@intel.com> Signed-off-by: Yuwei Chen <yuwei.chen@intel.com> Reviewed-by: Rebecca Cran <rebecca@bsdio.com>