[media] exynos4-is: Convert index variable to signed

index variable is used to check the validity of the data by
testing for negative values. Hence make it signed.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/exynos4-is/fimc-core.h

@@ -425,7 +425,7 @@ struct fimc_dev {
 	struct regmap			*sysreg;
 	const struct fimc_variant	*variant;
 	const struct fimc_drvdata	*drv_data;
-	u16				id;
+	int				id;
 	struct clk			*clock[MAX_FIMC_CLOCKS];
 	void __iomem			*regs;
 	wait_queue_head_t		irq_queue;

drivers/media/platform/exynos4-is/fimc-lite.h

@@ -140,7 +140,7 @@ struct fimc_lite {
 	struct v4l2_subdev	*sensor;
 	struct v4l2_ctrl_handler ctrl_handler;
 	struct v4l2_ctrl	*test_pattern;
-	u32			index;
+	int			index;
 	struct fimc_pipeline	pipeline;
 	const struct fimc_pipeline_ops *pipeline_ops;