block/partitions/ldm.c: Fix a kernel-doc warning

Fix the following kernel-doc warning that appears when building with W=1:

block/partitions/ldm.c:31: warning: expecting prototype for ldm().
Prototype was for ldm_debug() instead
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210805173447.3249906-1-bvanassche@acm.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/partitions/ldm.c

 // SPDX-License-Identifier: GPL-2.0-or-later
-/**
+/*
  * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
  *
  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>