iio: adc: stm32: Fix IRQs on STM32F4 by removing custom spurious IRQs message

The check for spurious IRQs introduced in 695e2f5c assumed that the bits
in the control and status registers are aligned. This is true for the H7 and MP1
version, but not the F4. The interrupt was then never handled on the F4.

Instead of increasing the complexity of the comparison and check each bit specifically,
we remove this check completely and rely on the generic handler for spurious IRQs.

Fixes: 695e2f5c

 ("iio: adc: stm32-adc: fix a regression when using dma and irq")
Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220516203939.3498673-3-yannick.brosseau@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>