pinctrl: use kasprintf() in pinmux_request_gpio()

Instead of using a temporary buffer, snprintf() and kstrdup(), just
use kasprintf() that does the same thing in just oneline.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Colin Cross <ccross@google.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinmux.c

@@ -232,14 +232,11 @@ int pinmux_request_gpio(struct pinctrl_dev *pctldev,
 			struct pinctrl_gpio_range *range,
 			unsigned pin, unsigned gpio)
 {
-	char gpiostr[16];
 	const char *owner;
 	int ret;
 
 	/* Conjure some name stating what chip and pin this is taken by */
-	snprintf(gpiostr, 15, "%s:%d", range->name, gpio);
-
-	owner = kstrdup(gpiostr, GFP_KERNEL);
+	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
 	if (!owner)
 		return -EINVAL;