phy: cpcap-usb: Simplify bool conversion

Fix the following coccicheck warning:
./drivers/phy/motorola/phy-cpcap-usb.c:146:31-36: WARNING: conversion to
bool not needed here

Reported-by: Abaci Robot <[e-mail]>
Signed-off-by: Yang Li <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/phy/motorola/phy-cpcap-usb.c

···
 
 	error = iio_read_channel_processed(ddata->vbus, &value);
 	if (error >= 0)
-		return value > 3900 ? true : false;
+		return value > 3900;
 
 	dev_err(ddata->dev, "error reading VBUS: %i\n", error);