dquot: cleanup dquot drop routine

Get rid of the drop 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_drop helper to __dquot_drop
and vfs_dq_drop to dquot_drop to have a consistent namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index d12f980..88b7197 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -122,7 +122,7 @@
 		/* Quota is already initialized in iput() */
 		ext2_xattr_delete_inode(inode);
 		dquot_free_inode(inode);
-		vfs_dq_drop(inode);
+		dquot_drop(inode);
 	}
 
 	es = EXT2_SB(sb)->s_es;
@@ -608,7 +608,7 @@
 	dquot_free_inode(inode);
 
 fail_drop:
-	vfs_dq_drop(inode);
+	dquot_drop(inode);
 	inode->i_flags |= S_NOQUOTA;
 	inode->i_nlink = 0;
 	unlock_new_inode(inode);