media: ccs: Fix return value from probe

rval wasn't set, resulting in probe returning zero instead of an error.

Fixes: de10c161 ("[media] smiapp: Get clock rate if it's not available through DT")
Reported-by: NZhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/ccs/ccs-core.c

@@ -3030,7 +3030,7 @@ static int ccs_probe(struct i2c_client *client)
 				dev_err(&client->dev,
 					"can't set clock freq, asked for %u but got %lu\n",
 					sensor->hwcfg.ext_clk, rate);
-				return rval;
+				return -EINVAL;
 			}
 		} else {
 			sensor->hwcfg.ext_clk = clk_get_rate(sensor->ext_clk);