UBIFS: use kmemdup rather than duplicating its implementation

The patch was generated using fixed coccinelle semantic patch
scripts/coccinelle/api/memdup.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2014320

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

fs/ubifs/lpt.c

@@ -1498,11 +1498,10 @@ static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
 	}
 
 	/* nnode is being committed, so copy it */
-	n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
+	n = kmemdup(nnode, sizeof(struct ubifs_nnode), GFP_NOFS);
 	if (unlikely(!n))
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(n, nnode, sizeof(struct ubifs_nnode));
 	n->cnext = NULL;
 	__set_bit(DIRTY_CNODE, &n->flags);
 	__clear_bit(COW_CNODE, &n->flags);
@@ -1549,11 +1548,10 @@ static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
 	}
 
 	/* pnode is being committed, so copy it */
-	p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
+	p = kmemdup(pnode, sizeof(struct ubifs_pnode), GFP_NOFS);
 	if (unlikely(!p))
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(p, pnode, sizeof(struct ubifs_pnode));
 	p->cnext = NULL;
 	__set_bit(DIRTY_CNODE, &p->flags);
 	__clear_bit(COW_CNODE, &p->flags);

fs/ubifs/tnc.c

@@ -198,11 +198,10 @@ static struct ubifs_znode *copy_znode(struct ubifs_info *c,
 {
 	struct ubifs_znode *zn;
 
-	zn = kmalloc(c->max_znode_sz, GFP_NOFS);
+	zn = kmemdup(znode, c->max_znode_sz, GFP_NOFS);
 	if (unlikely(!zn))
 		return ERR_PTR(-ENOMEM);
 
-	memcpy(zn, znode, c->max_znode_sz);
 	zn->cnext = NULL;
 	__set_bit(DIRTY_ZNODE, &zn->flags);
 	__clear_bit(COW_ZNODE, &zn->flags);