platform/mellanox: mlxreg-lc: fix error code in mlxreg_lc_create_static_devices()

This code should be using PTR_ERR() instead of IS_ERR(). And because
it's using the wrong "dev->client" pointer, the IS_ERR() check will be
false, meaning the function returns success.

Fixes: 62f9529b8d5c ("platform/mellanox: mlxreg-lc: Add initial support for Nvidia line card devices")
Signed-off-by: Dan Carpenter <[e-mail]>
Acked-by: Vadim Pasternak <[e-mail]>
Link: https://lore.kernel.org/r/20211110074346.GB5176@kili
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/mellanox/mlxreg-lc.c

···
 				int size)
 {
 	struct mlxreg_hotplug_device *dev = devs;
-	int i;
+	int i, ret;
 
 	/* Create static I2C device feeding by auxiliary or main power. */
 	for (i = 0; i < size; i++, dev++) {
···
 				dev->brdinfo->type, dev->nr, dev->brdinfo->addr);
 
 			dev->adapter = NULL;
+			ret = PTR_ERR(dev->client);
 			goto fail_create_static_devices;
 		}
 	}
···
 		i2c_unregister_device(dev->client);
 		dev->client = NULL;
 	}
-	return IS_ERR(dev->client);
+	return ret;
 }
 
 static void