platform/chrome: cros_usbpd_notify: Fix error handling in cros_usbpd_notify_init()

In the Linux kernel, the following vulnerability has been resolved:

platform/chrome: cros_usbpd_notify: Fix error handling in cros_usbpd_notify_init()

The following WARNING message was given when rmmod cros_usbpd_notify:

Unexpected driver unregister!
WARNING: CPU: 0 PID: 253 at drivers/base/driver.c:270 driver_unregister+0x8a/0xb0
Modules linked in: cros_usbpd_notify(-)
CPU: 0 PID: 253 Comm: rmmod Not tainted 6.1.0-rc3 #24
...
Call Trace:
<TASK>
cros_usbpd_notify_exit+0x11/0x1e [cros_usbpd_notify]
__x64_sys_delete_module+0x3c7/0x570
? __ia32_sys_delete_module+0x570/0x570
? lock_is_held_type+0xe3/0x140
? syscall_enter_from_user_mode+0x17/0x50
? rcu_read_lock_sched_held+0xa0/0xd0
? syscall_enter_from_user_mode+0x1c/0x50
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f333fe9b1b7

The reason is that the cros_usbpd_notify_init() does not check the return
value of platform_driver_register(), and the cros_usbpd_notify can
install successfully even if platform_driver_register() failed.

Fix by checking the return value of platform_driver_register() and
unregister cros_usbpd_notify_plat_driver when it failed.