clk: clk-wm831x: fix a logic error

Fix bug https://bugzilla.kernel.org/show_bug.cgi?id=188561. Function
wm831x_clkout_is_prepared() returns "true" when it fails to read
CLOCK_CONTROL_1. "true" means the device is already prepared. So
return "true" on the read failure seems improper.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Fixes: f05259a6 ("clk: wm831x: Add initial WM831x clock driver")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/clk-wm831x.c

@@ -243,7 +243,7 @@ static int wm831x_clkout_is_prepared(struct clk_hw *hw)
 	if (ret < 0) {
 		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
 			ret);
-		return true;
+		return false;
 	}
 
 	return (ret & WM831X_CLKOUT_ENA) != 0;