HID: hid-input: fix stylus battery reporting

With commit 4f38821 hid-input started clearing of "ignored" usages
to avoid using garbage that might have been left in them. However
"battery strength" usages should not be ignored, as we do want to
use them.

Fixes: 4f38821 ("HID: hid-input: clear unmapped usages")
Reported-by: Kenneth Albanowski <kenalba@google.com>
Tested-by: Kenneth Albanowski <kenalba@google.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-input.c

@@ -797,7 +797,7 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 		case 0x3b: /* Battery Strength */
 			hidinput_setup_battery(device, HID_INPUT_REPORT, field);
 			usage->type = EV_PWR;
-			goto ignore;
+			return;
 
 		case 0x3c: /* Invert */
 			map_key_clear(BTN_TOOL_RUBBER);
@@ -1059,7 +1059,7 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 		case HID_DC_BATTERYSTRENGTH:
 			hidinput_setup_battery(device, HID_INPUT_REPORT, field);
 			usage->type = EV_PWR;
-			goto ignore;
+			return;
 		}
 		goto unknown;