fix[script]: Optimize changelog.sh

Signed-off-by: Herman Chen <herman.chen@rock-chips.com>
Change-Id: I5029f2f57bfffc1b8331665b7dcf8a10523b457e

tools/changelog.sh

@@ -218,5 +218,7 @@ echo -e "${prev_changelog}" >> ${changelog_file}
 # add CHANGELOG.md
 git add ${changelog_file}
 git commit --amend -C ${curr_ver}
+# update tag message
+git tag -f ${version_tag} -m "${version_tag} version at ${tag_date}"
 
 IFS=$OLDIFS