ksmbd: return a literal instead of 'err' in ksmbd_vfs_kern_path_locked()

[ Upstream commit cf5e7f73

 ]

Return a literal instead of 'err' in ksmbd_vfs_kern_path_locked().

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>