platform/x86: apple-gmux: use resource_size() with res

stable inclusion
from stable-v5.10.90
commit 7da855e93964893d48df8ad60fc30a8ac8327506
bugzilla: 186168 https://gitee.com/openeuler/kernel/issues/I4SHY1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7da855e93964893d48df8ad60fc30a8ac8327506

--------------------------------

[ Upstream commit eb66fb03 ]

This should be (res->end - res->start + 1) here actually,
use resource_size() derectly.
Signed-off-by: NWang Qing <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1639484316-75873-1-git-send-email-wangqing@vivo.comReviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/platform/x86/apple-gmux.c

@@ -625,7 +625,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 	}
 
 	gmux_data->iostart = res->start;
-	gmux_data->iolen = res->end - res->start;
+	gmux_data->iolen = resource_size(res);
 
 	if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
 		pr_err("gmux I/O region too small (%lu < %u)\n",