drm: bridge: it66121: fix an error code in it66121_probe()

This code is passing the wrong variable to PTR_ERR() so it doesn't
return the correct error code.

Fixes: 988156dc ("drm: bridge: add it66121 driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YJ+ZX3BdKPAN0pUZ@mwanda

drivers/gpu/drm/bridge/ite-it66121.c

@@ -943,7 +943,7 @@ static int it66121_probe(struct i2c_client *client,
 	ctx->regmap = devm_regmap_init_i2c(client, &it66121_regmap_config);
 	if (IS_ERR(ctx->regmap)) {
 		ite66121_power_off(ctx);
-		return PTR_ERR(ctx);
+		return PTR_ERR(ctx->regmap);
 	}
 
 	regmap_read(ctx->regmap, IT66121_VENDOR_ID0_REG, &vendor_ids[0]);