drm/kmb: Fix error return code in kmb_hw_init()

When the call to platform_get_irq() to obtain the IRQ of the lcd fails, the
returned error code should be propagated. However, we currently do not
explicitly assign this error code to 'ret'. As a result, 0 was incorrectly
returned.

Fixes: 7f7b96a8 ("drm/kmb: Add support for KeemBay Display")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210513134639.6541-1-thunder.leizhen@huawei.com

drivers/gpu/drm/kmb/kmb_drv.c

@@ -137,6 +137,7 @@ static int kmb_hw_init(struct drm_device *drm, unsigned long flags)
 	/* Allocate LCD interrupt resources */
 	irq_lcd = platform_get_irq(pdev, 0);
 	if (irq_lcd < 0) {
+		ret = irq_lcd;
 		drm_err(&kmb->drm, "irq_lcd not found");
 		goto setup_fail;
 	}