cocci reported warning: !A || A && B is equivalent to !A || B. This fix
simplified the condition check to !A || B.

Fixes: 76a85704 ("spi: spi-mem: Allow controller supporting mem_ops without exec_op")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202303010051.HrHWSr9y-lkp@intel.com/Signed-off-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/r/20230307012004.414502-1-william.zhang@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>