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: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c
index c69682a..369ef53 100644
--- a/fs/nfs/blocklayout/extents.c
+++ b/fs/nfs/blocklayout/extents.c
@@ -110,13 +110,7 @@
 		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);