spi: s3c64xx: fix timeout counters in flush_fifo

In the s3c64xx_flush_fifo() code, the loops counter is post-decremented
in the do { } while(test && loops--) condition. This means the loops is
left at the unsigned equivalent of -1 if the loop times out. The test
after will never pass as if tests for loops == 0.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Fixes: 230d42d4 ("spi: Add s3c64xx SPI Controller driver")
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://patch.msgid.link/20240924134009.116247-2-ben.dooks@codethink.co.ukSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-s3c64xx.c

@@ -245,7 +245,7 @@ static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
 	loops = msecs_to_loops(1);
 	do {
 		val = readl(regs + S3C64XX_SPI_STATUS);
-	} while (TX_FIFO_LVL(val, sdd) && loops--);
+	} while (TX_FIFO_LVL(val, sdd) && --loops);
 
 	if (loops == 0)
 		dev_warn(&sdd->pdev->dev, "Timed out flushing TX FIFO\n");
@@ -258,7 +258,7 @@ static void s3c64xx_flush_fifo(struct s3c64xx_spi_driver_data *sdd)
 			readl(regs + S3C64XX_SPI_RX_DATA);
 		else
 			break;
-	} while (loops--);
+	} while (--loops);
 
 	if (loops == 0)
 		dev_warn(&sdd->pdev->dev, "Timed out flushing RX FIFO\n");