dquot: move dquot drop responsibility into the filesystem

Currently clear_inode calls vfs_dq_drop directly.  This means
we tie the quota code into the VFS.  Get rid of that and make the
filesystem responsible for the drop inside the ->clear_inode
superblock operation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index d929a82..4086fa5 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -131,6 +131,11 @@
 	kmem_cache_free(jfs_inode_cachep, ji);
 }
 
+static void jfs_clear_inode(struct inode *inode)
+{
+	vfs_dq_drop(inode);
+}
+
 static int jfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct jfs_sb_info *sbi = JFS_SBI(dentry->d_sb);
@@ -745,6 +750,7 @@
 	.dirty_inode	= jfs_dirty_inode,
 	.write_inode	= jfs_write_inode,
 	.delete_inode	= jfs_delete_inode,
+	.clear_inode	= jfs_clear_inode,
 	.put_super	= jfs_put_super,
 	.sync_fs	= jfs_sync_fs,
 	.freeze_fs	= jfs_freeze,