kselftest/alsa - mixer-test: fix the number of parameters to ksft_exit_fail_msg()

kselftest/alsa - mixer-test: fix the number of parameters to ksft_exit_fail_msg()

Minor fix in the number of arguments to error reporting function in the
test program as reported by GCC 13.2.0 warning.

mixer-test.c: In function ‘find_controls’:
mixer-test.c:169:44: warning: too many arguments for format [-Wformat-extra-args]
  169 |                         ksft_exit_fail_msg("snd_ctl_poll_descriptors() failed for %d\n",
      |                                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The number of arguments in call to ksft_exit_fail_msg() doesn't correspond
to the format specifiers, so this is adjusted resembling the sibling calls
to the error function.

Fixes: b1446bda56456 ("kselftest: alsa: Check for event generation when we write to controls")
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-sound@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240107173704.937824-2-mirsad.todorovac@alu.unizg.hr
Signed-off-by: Takashi Iwai <tiwai@suse.de>