tee: optee: remove need_resched() before cond_resched()

Testing need_resched() before cond_resched() is not needed as an
equivalent test is done internally in cond_resched(). So drop the
need_resched() test.

Fixes: dcb3b06d ("tee: optee: replace might_sleep with cond_resched")
Reviewed-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Tested-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>