[media] staging: media: davinci_vpfe: fix ipipe_mode type

The variable can take negative values.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/staging/media/davinci_vpfe/dm365_ipipe_hw.c

@@ -254,7 +254,7 @@ int config_ipipe_hw(struct vpfe_ipipe_device *ipipe)
 	void __iomem *ipipe_base = ipipe->base_addr;
 	struct v4l2_mbus_framefmt *outformat;
 	u32 color_pat;
-	u32 ipipe_mode;
+	int ipipe_mode;
 	u32 data_path;
 
 	/* enable clock to IPIPE */