HID: fix a couple of off-by-ones

There are a few very theoretical off-by-one bugs in report descriptor size
checking when performing a pre-parsing fixup. Fix those.

Cc: stable@vger.kernel.org
Reported-by: Ben Hawkes <hawkes@google.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
 static __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
 {
	if (*rsize >= 18 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
 		hid_info(hdev, "fixing up Cherry Cymotion report descriptor\n");
 		rdesc[11] = rdesc[16] = 0xff;
 		rdesc[12] = rdesc[17] = 0x03;
	}
	return rdesc;
}

 static __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
 {
	if (*rsize >= 17 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
 		hid_info(hdev, "fixing up Cherry Cymotion report descriptor\n");
 		rdesc[11] = rdesc[16] = 0xff;
 		rdesc[12] = rdesc[17] = 0x03;
	}
	return rdesc;
}
