pwm: imx: Signedness bug in imx_pwm_get_state()

"ret" only holds zero and negative error codes.  It needs to be signed
for the error handling to work.

Fixes: 9f4c8f96 ("pwm: imx: Add ipg clock operation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-imx27.c

@@ -115,8 +115,9 @@ static void pwm_imx27_get_state(struct pwm_chip *chip,
 				struct pwm_device *pwm, struct pwm_state *state)
 {
 	struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip);
-	u32 period, prescaler, pwm_clk, ret, val;
+	u32 period, prescaler, pwm_clk, val;
 	u64 tmp;
+	int ret;
 
 	ret = pwm_imx27_clk_prepare_enable(chip);
 	if (ret < 0)