nilfs2: use unlocked_ioctl

Pekka Enberg suggested converting ->ioctl operations to use
->unlocked_ioctl to avoid BKL.

The conversion was verified to be safe, so I will take it on this
occasion.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index 393316c..54100ac 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -702,7 +702,7 @@
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= nilfs_readdir,
-	.ioctl		= nilfs_ioctl,
+	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_ioctl,
 #endif	/* CONFIG_COMPAT */