Btrfs: do not set EXTENT_DIRTY along with EXTENT_DELALLOC

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0ada0b7..f284d4e 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1107,7 +1107,7 @@
 			struct extent_state **cached_state, gfp_t mask)
 {
 	return set_extent_bit(tree, start, end,
-			      EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE,
+			      EXTENT_DELALLOC | EXTENT_UPTODATE,
 			      0, NULL, cached_state, mask);
 }