HID: bpf: fix BTN_STYLUS for the XP Pen ACK05 remote

Usage_Dig_BarrelSwitch was applied in the UsagePage_Button
which incorrectly mapped to BTN_TOOL_PENCIL

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/193
Fixes: 834da37 ("bpf: add a v6.11+ compatible BPF fixup for the XPPen ACK05 remote")
Link: https://patchwork.kernel.org/project/linux-input/patch/20250207-bpf-import-2025-02-07-v1-7-6048fdd5a206@kernel.org/

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

Author: whot

drivers/hid/bpf/progs/XPPen__ACK05.bpf.c

@@ -157,6 +157,7 @@ static const __u8 fixed_rdesc_vendor[] = {
 			ReportCount(5) // padding
 			Input(Const)
 			// Byte 4 in report - just exists so we get to be a tablet pad
+			UsagePage_Digitizers
 			Usage_Dig_BarrelSwitch // BTN_STYLUS
 			ReportCount(1)
 			ReportSize(1)