btrfs: sink gfp parameter to clear_extent_bit

All callers use GFP_NOFS, we don't have to pass it as an argument. The
built-in tests pass GFP_KERNEL, but they run only at module load time
and NOFS works there as well.

Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 5a8c264..dac688c 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1016,8 +1016,7 @@ static int __btrfs_wait_marked_extents(struct btrfs_fs_info *fs_info,
 		 * it's safe to do it (through clear_btree_io_tree()).
 		 */
 		err = clear_extent_bit(dirty_pages, start, end,
-				       EXTENT_NEED_WAIT,
-				       0, 0, &cached_state, GFP_NOFS);
+				       EXTENT_NEED_WAIT, 0, 0, &cached_state);
 		if (err == -ENOMEM)
 			err = 0;
 		if (!err)