[GFS2] Remove unused constants

Three of the DIO constants were not being used, so remove them.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index a5630ec..6b52aac 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -120,8 +120,7 @@
 					gfs2_io_error_bh(sdp, bh);
 					gfs2_log_lock(sdp);
 				}
-				list_move(&bd->bd_ail_st_list,
-					  &ai->ai_ail2_list);
+				list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
 				continue;
 			}
 
@@ -411,9 +410,6 @@
 	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
 		return -EIO;
 
-	if (flags & DIO_FORCE)
-		clear_buffer_uptodate(bh);
-
 	if ((flags & DIO_START) && !buffer_uptodate(bh))
 		ll_rw_block(READ, 1, &bh);