spi: Remove a redundant test for master->running in spi_queued_transfer

We have tested master->running immediately after grab the master->queue_lock.
The status of master->running won't be changed until we release the lock.
Thus remove a redundant test for master->running.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>