Btrfs: Fix do_sync_file_range ifdefs (2.6.22)

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/file.c

@@ -961,7 +961,7 @@ out_nolock:
 		if (err < 0)
 			num_written = err;
 	} else if (num_written > 0 && (file->f_flags & O_DIRECT)) {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
 		do_sync_file_range(file, start_pos,
 				      start_pos + num_written - 1,
 				      SYNC_FILE_RANGE_WRITE |