f2fs: fix to disable compression on directory

It needs to call f2fs_disable_compressed_file() to disable
compression on directory.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c44afc5..c84442e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3849,10 +3849,12 @@ static inline u64 f2fs_disable_compressed_file(struct inode *inode)
 
 	if (!f2fs_compressed_file(inode))
 		return 0;
-	if (get_dirty_pages(inode))
-		return 1;
-	if (fi->i_compr_blocks)
-		return fi->i_compr_blocks;
+	if (S_ISREG(inode->i_mode)) {
+		if (get_dirty_pages(inode))
+			return 1;
+		if (fi->i_compr_blocks)
+			return fi->i_compr_blocks;
+	}
 
 	fi->i_flags &= ~F2FS_COMPR_FL;
 	stat_dec_compr_inode(inode);