gpio: fix wrong checking condition for gpio range

If index++ calculates from 0, the checking condition of "while
(index++)" fails & it doesn't check any more. It doesn't follow
the loop that used at here.

Replace it by endless loop at here. Then it keeps parsing
"gpio-ranges" property until it ends.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index a71a54a..5150df6 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -193,7 +193,7 @@
 	if (!np)
 		return;
 
-	do {
+	for (;; index++) {
 		ret = of_parse_phandle_with_args(np, "gpio-ranges",
 				"#gpio-range-cells", index, &pinspec);
 		if (ret)
@@ -222,8 +222,7 @@
 
 		if (ret)
 			break;
-
-	} while (index++);
+	}
 }
 
 #else