media: imx7-media-csi: don't store a floating pointer

if imx7_csi_try_fmt() fails, outcc variable won't be
initialized and csi->cc[IMX7_CSI_PAD_SRC] would be pointing
to a random location.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx7-media-csi.c

@@ -980,7 +980,7 @@ static int imx7_csi_get_fmt(struct v4l2_subdev *sd,
 	return ret;
 }
 
-static void imx7_csi_try_fmt(struct imx7_csi *csi,
+static int imx7_csi_try_fmt(struct imx7_csi *csi,
 			    struct v4l2_subdev_pad_config *cfg,
 			    struct v4l2_subdev_format *sdformat,
 			    const struct imx_media_pixfmt **cc)
@@ -992,7 +992,7 @@ static void imx7_csi_try_fmt(struct imx7_csi *csi,
 	in_fmt = imx7_csi_get_format(csi, cfg, IMX7_CSI_PAD_SINK,
 				     sdformat->which);
 	if (!in_fmt)
-		return;
+		return -EINVAL;
 
 	switch (sdformat->pad) {
 	case IMX7_CSI_PAD_SRC:
@@ -1023,8 +1023,10 @@ static void imx7_csi_try_fmt(struct imx7_csi *csi,
 						   false);
 		break;
 	default:
+		return -EINVAL;
 		break;
 	}
+	return 0;
 }
 
 static int imx7_csi_set_fmt(struct v4l2_subdev *sd,
@@ -1067,8 +1069,10 @@ static int imx7_csi_set_fmt(struct v4l2_subdev *sd,
 		format.pad = IMX7_CSI_PAD_SRC;
 		format.which = sdformat->which;
 		format.format = sdformat->format;
-		imx7_csi_try_fmt(csi, cfg, &format, &outcc);
-
+		if (imx7_csi_try_fmt(csi, cfg, &format, &outcc)) {
+			ret = -EINVAL;
+			goto out_unlock;
+		}
 		outfmt = imx7_csi_get_format(csi, cfg, IMX7_CSI_PAD_SRC,
 					     sdformat->which);
 		*outfmt = format.format;