Input: iqs5xx - preserve bootloader errors

After user space writes the fw_file attribute to push new firmware
to the device, the driver calls iqs5xx_dev_init() to re-initialize
the device with the updated firmware or recover the device in case
the update failed.

In the case of the latter, however, iqs5xx_fw_file_write() returns
zero (success) so long as iqs5xx_dev_init() does not fail, and any
error encountered during the update process is lost. Solve this by
saving the error before calling iqs5xx_dev_init().

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/1611002626-5889-3-git-send-email-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/iqs5xx.c

@@ -883,7 +883,7 @@ static int iqs5xx_fw_file_parse(struct i2c_client *client,
 static int iqs5xx_fw_file_write(struct i2c_client *client, const char *fw_file)
 {
 	struct iqs5xx_private *iqs5xx = i2c_get_clientdata(client);
-	int error;
+	int error, error_bl;
 	u8 *pmap;
 
 	if (iqs5xx->bl_status == IQS5XX_BL_STATUS_NONE)
@@ -937,6 +937,7 @@ static int iqs5xx_fw_file_write(struct i2c_client *client, const char *fw_file)
 		usleep_range(10000, 10100);
 	}
 
+	error_bl = error;
 	error = iqs5xx_dev_init(client);
 	if (!error && iqs5xx->bl_status == IQS5XX_BL_STATUS_RESET)
 		error = -EINVAL;
@@ -948,6 +949,9 @@ static int iqs5xx_fw_file_write(struct i2c_client *client, const char *fw_file)
 err_kfree:
 	kfree(pmap);
 
+	if (error_bl)
+		return error_bl;
+
 	return error;
 }