submodule: Fix t7400, t7405, t7406 for msysGit

Again, avoid using echo (which issues DOS line endings on msysGit) to not mix
with Unix line-endings issued by git built-ins, even if this is at the cost of
calling an external executable (cat) instead of a shell built-in (echo).

git-sh-setup.sh

@@ -59,7 +59,9 @@ GIT_QUIET=
 say () {
 	if test -z "$GIT_QUIET"
 	then
-		printf '%s\n' "$*"
+		cat <<EOF
+$*
+EOF
 	fi
 }