dquot: cleanup dquot transfer routine

Get rid of the transfer dquot operation - it is now always called from
the filesystem and if a filesystem really needs it's own (which none
currently does) it can just call into it's own routine directly.

Rename the now static low-level dquot_transfer helper to __dquot_transfer
and vfs_dq_transfer to dquot_transfer to have a consistent namespace,
and make the new dquot_transfer return a normal negative errno value
which all callers expect.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index f56a3d2..99a5e5a 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3134,8 +3134,7 @@
 						  jbegin_count);
 				if (error)
 					goto out;
-				error =
-				    vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
+				error = dquot_transfer(inode, attr);
 				if (error) {
 					journal_end(&th, inode->i_sb,
 						    jbegin_count);