hte: Fix off by one in hte_push_ts_ns()

The &chip->gdev->ei[] array has chip->nlines elements so this >
comparison needs to be >= to prevent an out of bounds access. The
gdev->ei[] array is allocated in hte_register_chip().

Fixes: 31ab09b4 ("drivers: Add hardware timestamp engine (HTE) subsystem")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dipen Patel <dipenp@nvidia.com>
Acked-by: Dipen Patel <dipenp@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>