i2c: npcm7xx: Add check for platform_driver_register

As platform_driver_register() could fail, it should be better
to deal with the return value in order to maintain the code
consisitency.

Fixes: 56a1485b ("i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Acked-by: Tali Perry <tali.perry1@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-npcm7xx.c

@@ -2372,8 +2372,7 @@ static struct platform_driver npcm_i2c_bus_driver = {
 static int __init npcm_i2c_init(void)
 {
 	npcm_i2c_debugfs_dir = debugfs_create_dir("npcm_i2c", NULL);
-	platform_driver_register(&npcm_i2c_bus_driver);
-	return 0;
+	return platform_driver_register(&npcm_i2c_bus_driver);
 }
 module_init(npcm_i2c_init);