serial: 8250_pci: Refactor the loop in pci_ite887x_init()

stable inclusion
from stable-v5.10.137
commit 297e2fd08a58d4fe79ec1632ee2404b1a1484c5a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=297e2fd08a58d4fe79ec1632ee2404b1a1484c5a

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

[ Upstream commit 35b4f172 ]

The loop can be refactored by using ARRAY_SIZE() instead of NULL terminator.
This reduces code base and makes it easier to read and understand.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NJiri Slaby <jslaby@kernel.org>
Link: https://lore.kernel.org/r/20211022135147.70965-1-andriy.shevchenko@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

drivers/tty/serial/8250/8250_pci.c

@@ -897,18 +897,16 @@ static int pci_netmos_init(struct pci_dev *dev)
 /* enable IO_Space bit */
 #define ITE_887x_POSIO_ENABLE		(1 << 31)
 
+/* inta_addr are the configuration addresses of the ITE */
+static const short inta_addr[] = { 0x2a0, 0x2c0, 0x220, 0x240, 0x1e0, 0x200, 0x280 };
 static int pci_ite887x_init(struct pci_dev *dev)
 {
-	/* inta_addr are the configuration addresses of the ITE */
-	static const short inta_addr[] = { 0x2a0, 0x2c0, 0x220, 0x240, 0x1e0,
-							0x200, 0x280, 0 };
 	int ret, i, type;
 	struct resource *iobase = NULL;
 	u32 miscr, uartbar, ioport;
 
 	/* search for the base-ioport */
-	i = 0;
-	while (inta_addr[i] && iobase == NULL) {
+	for (i = 0; i < ARRAY_SIZE(inta_addr); i++) {
 		iobase = request_region(inta_addr[i], ITE_887x_IOSIZE,
 								"ite887x");
 		if (iobase != NULL) {
@@ -925,12 +923,10 @@ static int pci_ite887x_init(struct pci_dev *dev)
 				break;
 			}
 			release_region(iobase->start, ITE_887x_IOSIZE);
-			iobase = NULL;
 		}
-		i++;
 	}
 
-	if (!inta_addr[i]) {
+	if (i == ARRAY_SIZE(inta_addr)) {
 		dev_err(&dev->dev, "ite887x: could not find iobase\n");
 		return -ENODEV;
 	}