ext4: fix ext4_mb_clear_bb() kernel-doc comment

Remove the excess description of @bh in ext4_mb_clear_bb() kernel-doc
comment to remove warnings found by running scripts/kernel-doc, which
is caused by using 'make W=1'.

fs/ext4/mballoc.c:5895: warning: Excess function parameter 'bh'
description in 'ext4_mb_clear_bb'
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220301092136.34764-1-yang.lee@linux.alibaba.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -5884,7 +5884,6 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
  *			Used by ext4_free_blocks()
  * @handle:		handle for this transaction
  * @inode:		inode
- * @bh:			optional buffer of the block to be freed
  * @block:		starting physical block to be freed
  * @count:		number of blocks to be freed
  * @flags:		flags used by ext4_free_blocks