pinctrl: pinctrl-at91.c: Cleaning up if unsigned is less than zero

Remove checking if a unsigned is less than zero

This was found using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-at91.c

@@ -924,7 +924,7 @@ static int at91_pinctrl_parse_functions(struct device_node *np,
 	/* Initialise function */
 	func->name = np->name;
 	func->ngroups = of_get_child_count(np);
-	if (func->ngroups <= 0) {
+	if (func->ngroups == 0) {
 		dev_err(info->dev, "no groups defined\n");
 		return -EINVAL;
 	}