NFS: Clean up nfs_sync_mapping

Remove the redundant call to filemap_write_and_wait().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/inode.c

@@ -114,16 +114,12 @@ void nfs_clear_inode(struct inode *inode)
  */
 int nfs_sync_mapping(struct address_space *mapping)
 {
-	int ret;
+	int ret = 0;
 
-	if (mapping->nrpages == 0)
-		return 0;
+	if (mapping->nrpages != 0) {
 		unmap_mapping_range(mapping, 0, 0, 0);
-	ret = filemap_write_and_wait(mapping);
-	if (ret != 0)
-		goto out;
 		ret = nfs_wb_all(mapping->host);
-out:
+	}
 	return ret;
 }