media: exynos4-is: Add missed check for pinctrl_lookup_state()

fimc_md_get_pinctrl() misses a check for pinctrl_lookup_state().
Add the missed check to fix it.

Fixes: 4163851f7b ("[media] s5p-fimc: Use pinctrl API for camera ports configuration]")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/exynos4-is/media-dev.c

@@ -1270,6 +1270,9 @@ static int fimc_md_get_pinctrl(struct fimc_md *fmd)
 
 	pctl->state_idle = pinctrl_lookup_state(pctl->pinctrl,
 					PINCTRL_STATE_IDLE);
+	if (IS_ERR(pctl->state_idle))
+		return PTR_ERR(pctl->state_idle);
+
 	return 0;
 }