sys/usb_cdc_acm_stdio: only submit and flush for non-empty buffer #31761

	name: tools-buildtest

	on:
	push:
	branches:
	- master
	- staging
	- trying
	tags:
	- '*'
	pull_request:
	branches:
	- '*'
	merge_group:

	jobs:
	tools-build:
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	max-parallel: 16
	matrix:
	tools: # List of tools sorted by name in alphabetical order
	- name: benchmark_udp
	path: dist/tools
	- name: bossa-1.8
	path: dist/tools
	- name: bossa-1.9
	path: dist/tools
	- name: bossa-nrf52
	path: dist/tools
	- name: calc_spi_scalers
	path: cpu/kinetis/dist
	- name: clk_conf
	path: cpu/stm32/dist
	- name: edbg
	path: dist/tools
	- name: ethos
	path: dist/tools
	- name: fixdep
	path: dist/tools
	- name: flatc
	path: dist/tools
	- name: lpc2k_pgm
	path: dist/tools
	- name: mosquitto_rsmb
	path: dist/tools
	- name: riotboot_serial
	path: dist/tools
	- name: setsid
	path: dist/tools
	- name: uhcpd
	path: dist/tools
	- name: zep_dispatch
	path: dist/tools
	steps:
	- uses: actions/checkout@main
	- name: Build ${{ matrix.tools.name }} in ${{ matrix.tools.path }}
	uses: aabadie/riot-action@main
	with:
	cmd: make -C ${{ matrix.tools.path }}/${{ matrix.tools.name }}
	tools-build-success:
	if: always()
	needs: tools-build
	runs-on: ubuntu-latest
	steps:
	- name: tools-build succeeded
	uses: re-actors/alls-green@release/v1
	with:
	jobs: ${{ toJSON(needs) }}

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