spi: fsi: Fix spurious timeout

The driver may return a timeout error even if the status register
indicates that the transfer may proceed. Fix this by restructuring
the polling loop.

Fixes: 89b35e3f ("spi: fsi: Implement a timeout for polling status")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220525165852.33167-2-eajames@linux.ibm.com


Signed-off-by: Mark Brown <broonie@kernel.org>