dell-led: remove GUID check from dell_micmute_led_set()

As dell_micmute_led_set() no longer uses the dell_wmi_perform_query()
method, which was removed in commit 0c41a08e ("dell-led: use
dell_smbios_send_request() for performing SMBIOS calls"), the
DELL_APP_GUID check is redundant and thus can be safely removed.
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Tested-by: Alex Hung <alex.hung@canonical.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

drivers/leds/dell-led.c

@@ -51,9 +51,6 @@ static int dell_micmute_led_set(int state)
 	struct calling_interface_buffer *buffer;
 	struct calling_interface_token *token;
 
-	if (!wmi_has_guid(DELL_APP_GUID))
-		return -ENODEV;
-
 	if (state == 0)
 		token = dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE);
 	else if (state == 1)