spi: fsl-cpm: Correct the free:ing

The fsl_spi_cpm_free() function does not make the same
checks as the error path in fsl_spi_cpm_init() leading
to crashes on error.

Cc: Fabio Estevam <festevam@gmail.com>
Reported-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191113014442.12100-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-cpm.c

@@ -392,7 +392,8 @@ void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
 	dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
 	dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
 	cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
-	cpm_muram_free(cpm_muram_offset(mspi->pram));
+	if (!(mspi->flags & SPI_CPM1))
+		cpm_muram_free(cpm_muram_offset(mspi->pram));
 	fsl_spi_free_dummy_rx();
 }
 EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);