pNFS: Handle allocation errors correctly in objlayout_alloc_layout_hdr()

Return the NULL pointer when the allocation fails.

Cc: Boaz Harrosh <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/objlayout/objlayout.c

···
 	struct objlayout *objlay;
 
 	objlay = kzalloc(sizeof(struct objlayout), gfp_flags);
-	if (objlay) {
-		spin_lock_init(&objlay->lock);
-		INIT_LIST_HEAD(&objlay->err_list);
-	}
+	if (!objlay)
+		return NULL;
+	spin_lock_init(&objlay->lock);
+	INIT_LIST_HEAD(&objlay->err_list);
 	dprintk("%s: Return %p\n", __func__, objlay);
 	return &objlay->pnfs_layout;
 }