pwm: sifive: Simplify if-if to if-else

Use if and else instead of if(A) and if (!A).
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-sifive.c

@@ -138,10 +138,9 @@ static int pwm_sifive_enable(struct pwm_chip *chip, bool enable)
 			dev_err(ddata->chip.dev, "Enable clk failed\n");
 			return ret;
 		}
-	}
-
-	if (!enable)
+	} else {
 		clk_disable(ddata->clk);
+	}
 
 	return 0;
 }