LU-6142 lustre: remove remaining users of ldebugfs_register

LU-6142 lustre: remove remaining users of ldebugfs_register

ldebugfs_register() is just a call to debugfs_create_dir() and
ldebugfs_add_vars() if the list option is set.  Fix up the remaining
users of this function to just call these two functions instead, and
delete the now unused ldebugfs_register() call.

This ends up cleaning up more code and making things smaller, always a
good thing.

Linux-Commit 00905f006608 ("staging: lustre: remove last two
	users of ldebugfs_register()")

Test-Parameters: trivial
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I08f4cdcdd3367f50c37d899a5dc4d753e72c0fda
Reviewed-on: https://review.whamcloud.com/37743
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>