f2fs: fix to account compressed inode correctly

stat_inc_compr_inode() needs to check FI_COMPRESSED_FILE flag, so
in f2fs_disable_compressed_file(), we should call stat_dec_compr_inode()
before clearing FI_COMPRESSED_FILE flag.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -3824,8 +3824,8 @@ static inline u64 f2fs_disable_compressed_file(struct inode *inode)
 		return fi->i_compr_blocks;
 
 	fi->i_flags &= ~F2FS_COMPR_FL;
-	clear_inode_flag(inode, FI_COMPRESSED_FILE);
 	stat_dec_compr_inode(inode);
+	clear_inode_flag(inode, FI_COMPRESSED_FILE);
 	return 0;
 }