pinctrl: pinctrl-imx.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: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-imx.c

@@ -515,7 +515,7 @@ static int imx_pinctrl_parse_functions(struct device_node *np,
 	/* Initialise function */
 	func->name = np->name;
 	func->num_groups = of_get_child_count(np);
-	if (func->num_groups <= 0) {
+	if (func->num_groups == 0) {
 		dev_err(info->dev, "no groups defined in %s\n", np->full_name);
 		return -EINVAL;
 	}