vt8500_pwm_remove() is only called after vt8500_pwm_probe() returned
successfully. In this case driver data was set to a non-NULL value
and so chip can never be NULL.

While touching this code also put declaration and assignment in a single
line.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>