power: supply: cw2015: use dev_err_probe to allow deferred probe

Deal with deferred probe using dev_err_probe so the error is handled
and avoid logging lots probe defer information like the following:

[ 9.125121] cw2015 4-0062: Failed to register power supply
[ 9.211131] cw2015 4-0062: Failed to register power supply

Fixes: b4c7715c10c1 ("power: supply: add CellWise cw2015 fuel gauge driver")
Signed-off-by: Peter Robinson <[e-mail]>
Reviewed-by: Javier Martinez Canillas <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/cw2015_battery.c

···
 						    &cw2015_bat_desc,
 						    &psy_cfg);
 	if (IS_ERR(cw_bat->rk_bat)) {
-		dev_err(cw_bat->dev, "Failed to register power supply\n");
+		/* try again if this happens */
+		dev_err_probe(&client->dev, PTR_ERR(cw_bat->rk_bat),
+			"Failed to register power supply\n");
 		return PTR_ERR(cw_bat->rk_bat);
 	}