pnfsblock: clean up _add_entry

It is wrong to kmalloc in _add_entry() as it is inside
spinlock. memory should be already allocated _add_entry() is called.
Signed-off-by: NPeng Tao <peng_tao@emc.com>
Signed-off-by: NBenny Halevy <bhalevy@tonian.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/blocklayout/extents.c

@@ -110,13 +110,7 @@ static int _add_entry(struct my_tree *tree, u64 s, int32_t tag,
 		return 0;
 	} else {
 		struct pnfs_inval_tracking *new;
-		if (storage)
-			new = storage;
-		else {
-			new = kmalloc(sizeof(*new), GFP_NOFS);
-			if (!new)
-				return -ENOMEM;
-		}
+		new = storage;
 		new->it_sector = s;
 		new->it_tags = (1 << tag);
 		list_add(&new->it_link, &pos->it_link);