fix(init): replace remaining non-POSIX echo -e with printf (#2115)

Author: fiftydinar

internal/inside-distrobox/assets/distrobox-init

@@ -532,7 +532,7 @@ setup_pacman_exceptions()
 		# This will be removed if we're using --init.
 		cat << EOF > /usr/share/libalpm/scripts/distrobox_post_hook.sh
 #!/bin/sh
-echo -e '#!/bin/sh\nexit 0' > /usr/share/libalpm/scripts/systemd-hook;
+printf '#!/bin/sh\nexit 0\n' > /usr/share/libalpm/scripts/systemd-hook;
 EOF
 		chmod +x /usr/share/libalpm/scripts/distrobox_post_hook.sh