Btrfs, replace: enable dev-replace for raid56

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

fs/btrfs/dev-replace.c

@@ -316,11 +316,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
 	struct btrfs_device *tgt_device = NULL;
 	struct btrfs_device *src_device = NULL;
 
-	if (btrfs_fs_incompat(fs_info, RAID56)) {
-		btrfs_warn(fs_info, "dev_replace cannot yet handle RAID5/RAID6");
-		return -EOPNOTSUPP;
-	}
-
 	switch (args->start.cont_reading_from_srcdev_mode) {
 	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS:
 	case BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID: