regulator: ab8500 - fix the logic to remove already registered regulators in error path

In current implementation, ab8500_regulator_info[0].regulator is not
unregistered if the error happen at i > 0.

This patch fixes the resource leak and also improves the readability.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/ab8500.c

@@ -369,11 +369,9 @@ static __devinit int ab8500_regulator_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "failed to register regulator %s\n",
 					info->desc.name);
 			/* when we fail, un-register all earlier regulators */
-			i--;
-			while (i > 0) {
+			while (--i >= 0) {
 				info = &ab8500_regulator_info[i];
 				regulator_unregister(info->regulator);
-				i--;
 			}
 			return err;
 		}