ALSA: hda - Fix incorrect clearance of thinkpad_acpi hooks

Since the commit c647f806b8 ("ALSA: hda - Allow multiple ADCs for
mic mute LED controls") we allow enabling the mic mute LED with
multiple ADCs.  The commit changed the function return value to be
zero or a negative error, while this change was overlooked in the
thinkpad_acpi helper code where it still expects a positive return
value for success.  This eventually leads to a NULL dereference on a
system that has only a mic mute LED.

This patch corrects the return value check in the corresponding code
as well.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201621
Fixes: c647f806b8 ("ALSA: hda - Allow multiple ADCs for mic mute LED controls")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/thinkpad_helper.c

@@ -58,8 +58,8 @@ static void hda_fixup_thinkpad_acpi(struct hda_codec *codec,
 			removefunc = false;
 		}
 		if (led_set_func(TPACPI_LED_MICMUTE, false) >= 0 &&
-		    snd_hda_gen_add_micmute_led(codec,
-						update_tpacpi_micmute) > 0)
+		    !snd_hda_gen_add_micmute_led(codec,
+						 update_tpacpi_micmute))
 			removefunc = false;
 	}