dm: spi: Add logging of some return values

When SPI flash operations fail it is helpful to be able to see the error
codes and where they are generated. Add logging to capture this
information for read operations.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index 42c7cde..94fde2a 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -97,7 +97,7 @@
 {
 	struct spi_flash *flash = dev_get_uclass_priv(dev);
 
-	return spi_flash_cmd_read_ops(flash, offset, len, buf);
+	return log_ret(spi_flash_cmd_read_ops(flash, offset, len, buf));
 }
 
 static int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,