btrfs: SETFLAGS ioctl: use helper for compression type conversion

Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ioctl.c

@@ -307,12 +307,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 		ip->flags |= BTRFS_INODE_COMPRESS;
 		ip->flags &= ~BTRFS_INODE_NOCOMPRESS;
 
-		if (fs_info->compress_type == BTRFS_COMPRESS_LZO)
-			comp = "lzo";
-		else if (fs_info->compress_type == BTRFS_COMPRESS_ZLIB)
-			comp = "zlib";
-		else
-			comp = "zstd";
+		comp = btrfs_compress_type2str(fs_info->compress_type);
+		if (!comp || comp[0] == 0)
+			comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
+
 		ret = btrfs_set_prop(inode, "btrfs.compression",
 				     comp, strlen(comp), 0);
 		if (ret)