nfs: Take advantage of kmem_cache_zalloc() in nfs_page_alloc()

Take advantage of kmem_cache_zalloc() in nfs_page_alloc(). Save a call to
memset() and a few bytes.

Before:
 [jj@dragon linux-2.6]$ size fs/nfs/pagelist.o
    text    data     bss     dec     hex filename
    1765       0       8    1773     6ed fs/nfs/pagelist.o
After:
 [jj@dragon linux-2.6]$ size fs/nfs/pagelist.o
    text    data     bss     dec     hex filename
    1749       0       8    1757     6dd fs/nfs/pagelist.o
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/pagelist.c

@@ -26,12 +26,9 @@ static struct kmem_cache *nfs_page_cachep;
 static inline struct nfs_page *
 nfs_page_alloc(void)
 {
-	struct nfs_page	*p;
-	p = kmem_cache_alloc(nfs_page_cachep, GFP_KERNEL);
-	if (p) {
-		memset(p, 0, sizeof(*p));
+	struct nfs_page	*p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
+	if (p)
 		INIT_LIST_HEAD(&p->wb_list);
-	}
 	return p;
 }