pwm: ep93xx: Fix read of uninitialized variable ret

There is a potential path in function ep93xx_pwm_apply where ret is
never assigned a value and it is checked for an error code. Fix this
by ensuring ret is zero'd in the success path to avoid this issue.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: f6ef94e ("pwm: ep93xx: Unfold legacy callbacks into ep93xx_pwm_apply()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-ep93xx.c

@@ -137,6 +137,7 @@ static int ep93xx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 				writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
 				writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
 			}
+			ret = 0;
 		} else {
 			ret = -EINVAL;
 		}