delete unused returned variable from gauss_newton() #185

	name: cpu-macos-build-and-test

	on:
	push:
	paths-ignore:
	- '**.md'
	- 'images/**'
	pull_request:
	paths-ignore:
	- '**.md'
	- 'images/**'

	jobs:
	build:
	name: Build and test

	strategy:
	matrix:
	config: [ '', '-DPBRT_DBG_LOGGING=True', '-DPBRT_FLOAT_AS_DOUBLE=True' ]
	fail-fast: false

	runs-on: macos-latest

	steps:
	- name: Checkout pbrt
	uses: actions/checkout@v3
	with:
	submodules: true

	- name: Checkout rgb2spectrum tables
	uses: actions/checkout@v3
	with:
	repository: mmp/rgb2spectrum
	path: build

	- name: Get cmake
	uses: lukka/get-cmake@latest

	- name: Install OpenEXR
	env:
	HOMEBREW_NO_INSTALL_CLEANUP: 1
	run: brew install openexr

	- name: Configure
	run: \|
	cd build
	cmake .. -DPBRT_USE_PREGENERATED_RGB_TO_SPECTRUM_TABLES=True ${{ matrix.config }}

	- name: Build
	run: cmake --build build --parallel --config Release

	- name: Test
	if: ${{ matrix.config == '' }}
	run: ./pbrt_test
	working-directory: build

Provide feedback