ALSA: kunit: use const qualifier for immutable data

Some data for testing is immutable. In the case, the const qualifier is
available for any loader to place it to read-only segment.

Fixes: 3e39acf5 ("ALSA: core: Add sound core KUnit test")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-ID: <20240425233653.218434-1-o-takashi@sakamocchi.jp>

sound/core/sound_kunit.c

@@ -45,7 +45,7 @@ struct avail_test_data {
 	snd_pcm_uframes_t expected_avail;
 };
 
-static struct snd_format_test_data valid_fmt[] = {
+static const struct snd_format_test_data valid_fmt[] = {
 	DEFINE_FORMAT(S8, 8, 8, -1, 1, SILENCE()),
 	DEFINE_FORMAT(U8, 8, 8, -1, 0, SILENCE(0x80)),
 	DEFINE_FORMAT(S16_LE, 16, 16, 1, 1, SILENCE()),
@@ -154,7 +154,7 @@ static void test_format_endianness(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, snd_pcm_format_big_endian(WRONG_FORMAT_2), -EINVAL);
 }
 
-static void _test_fill_silence(struct kunit *test, struct snd_format_test_data *data,
+static void _test_fill_silence(struct kunit *test, const struct snd_format_test_data *data,
 			       u8 *buffer, size_t samples_count)
 {
 	size_t sample_bytes = data->physical_bits >> 3;
@@ -191,7 +191,7 @@ static snd_pcm_uframes_t calculate_boundary(snd_pcm_uframes_t buffer_size)
 	return boundary;
 }
 
-static struct avail_test_data p_avail_data[] = {
+static const struct avail_test_data p_avail_data[] = {
 	/* buf_size + hw_ptr < appl_ptr => avail = buf_size + hw_ptr - appl_ptr + boundary */
 	{ 128, 1000, 1129, 1073741824UL - 1 },
 	/*
@@ -220,7 +220,7 @@ static void test_playback_avail(struct kunit *test)
 	}
 }
 
-static struct avail_test_data c_avail_data[] = {
+static const struct avail_test_data c_avail_data[] = {
 	/* hw_ptr - appl_ptr < 0 => avail = hw_ptr - appl_ptr + boundary */
 	{ 128, 1000, 1001, 1073741824UL - 1 },
 	/* standard case: avail = hw_ptr - appl_ptr */