leds: flash: leds-qcom-flash: Fix an unsigned comparison which can never be negative

The variable 'count' is defined as unsigned type, so the following if
statement is invalid, we can modify the type of count to int.

if (count <= 0) {
	dev_err(dev, "No led-sources specified\n");
	return -ENODEV;
}

./drivers/leds/flash/leds-qcom-flash.c:546:5-10: WARNING: Unsigned expression compared with zero: count <= 0.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5344


Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230531053559.5702-1-jiapeng.chong@linux.alibaba.com