spi/s3c64xx: Do not ignore return value of spi_master_resume/suspend

During PM resume and suspend do not ignore the return value of
spi_master_suspend() or spi_master_resume(). Instead pass it further.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>