pinctrl: msm: drop negativity check on unsigned value

[linux-3.16-rc5/drivers/pinctrl/pinctrl-msm.c:145]: (style) Checking if
unsigned variable 'mux_bit' is less than zero.

    if (WARN_ON(g->mux_bit < 0))
        return -EINVAL;

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=80491
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/qcom/pinctrl-msm.c

@@ -142,9 +142,6 @@ static int msm_pinmux_enable(struct pinctrl_dev *pctldev,
 
 	g = &pctrl->soc->groups[group];
 
-	if (WARN_ON(g->mux_bit < 0))
-		return -EINVAL;
-
 	for (i = 0; i < g->nfuncs; i++) {
 		if (g->funcs[i] == function)
 			break;