f2fs: fix return value in f2fs_ioc_commit_atomic_write

In f2fs_ioc_commit_atomic_write, if file is volatile, return -EINVAL to
indicate that commit failure.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -1726,8 +1726,10 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
 
 	down_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
 
-	if (f2fs_is_volatile_file(inode))
+	if (f2fs_is_volatile_file(inode)) {
+		ret = -EINVAL;
 		goto err_out;
+	}
 
 	if (f2fs_is_atomic_file(inode)) {
 		ret = commit_inmem_pages(inode);