f2fs: compress: remove unneeded code

- f2fs_write_multi_pages
 - f2fs_compress_pages
  - init_compress_ctx
  - compress_pages
  - destroy_compress_ctx  --- 1
 - f2fs_write_compressed_pages
 - destroy_compress_ctx  --- 2

destroy_compress_ctx() in f2fs_write_multi_pages() is redundant, remove
it.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/compress.c

@@ -1388,9 +1388,6 @@ int f2fs_write_multi_pages(struct compress_ctx *cc,
 					struct writeback_control *wbc,
 					enum iostat_type io_type)
 {
-	struct f2fs_inode_info *fi = F2FS_I(cc->inode);
-	const struct f2fs_compress_ops *cops =
-			f2fs_cops[fi->i_compress_algorithm];
 	int err;
 
 	*submitted = 0;
@@ -1405,7 +1402,6 @@ int f2fs_write_multi_pages(struct compress_ctx *cc,
 
 		err = f2fs_write_compressed_pages(cc, submitted,
 							wbc, io_type);
-		cops->destroy_compress_ctx(cc);
 		kfree(cc->cpages);
 		cc->cpages = NULL;
 		if (!err)