[PATCH -next] fs: 9p: fix wrong pointer passed to IS_ERR() and PTR_ERR()

[Yang Yingliang]

IS_ERR() and PTR_ERR() use wrong pointer, it should be
writeback_fid, fix it.

Fixes: 5bfe97d7382b ("9p: Fix writeback fid incorrectly being attached to dentry")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
 fs/9p/vfs_file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 649f04f112dc..59c32c9b799f 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -86,8 +86,8 @@ int v9fs_file_open(struct inode *inode, struct file *file)
 		 * to work.
 		 */
 		writeback_fid = v9fs_writeback_fid(file_dentry(file));
-		if (IS_ERR(fid)) {
-			err = PTR_ERR(fid);
+		if (IS_ERR(writeback_fid)) {
+			err = PTR_ERR(writeback_fid);
 			mutex_unlock(&v9inode->v_mutex);
 			goto out_error;
 		}
-- 
2.25.1