azure: Add -E back for the world build script

Commit dd5c954e ("travis/gitlab/azure: Use -W to avoid warnings check")
added -W to avoid warnings check, but it mistakenly dropped -E for
the world build script in the azure pipelines.

This caused builds on the azure pipelines fail to report warnings. Let's
add it back.

Fixes: dd5c954e ("travis/gitlab/azure: Use -W to avoid warnings check")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

.azure-pipelines.yml

@@ -458,7 +458,7 @@ jobs:
           cat << "EOF" >> build.sh
           if [[ "${BUILDMAN}" != "" ]]; then
               ret=0;
-              tools/buildman/buildman -o /tmp -P -W ${BUILDMAN} ${OVERRIDE} || ret=$?;
+              tools/buildman/buildman -o /tmp -P -E -W ${BUILDMAN} ${OVERRIDE} || ret=$?;
               if [[ $ret -ne 0 ]]; then
                   tools/buildman/buildman -o /tmp -seP ${BUILDMAN};
                   exit $ret;