spi: stm32: fix excluded_middle.cocci warnings

drivers/spi/spi-stm32.c:915:23-25: WARNING !A || A && B is equivalent to !A || B

 Condition !A || A && B is equivalent to !A || B.

Generated by: scripts/coccinelle/misc/excluded_middle.cocci

Fixes: 7ceb0b8a ("spi: stm32: finalize message either on dma callback or EOT")
CC: Alain Volmat <alain.volmat@foss.st.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Reviewed-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/20210713191004.GA14729@5eb5c2cbef84


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