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>
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index dc9f27e..9a51710 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -1498,11 +1498,10 @@
 	}
 
 	/* 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 @@
 	}
 
 	/* 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);