drivers/char: suspected null-pointer dereference problem in handle_control_message

[YE Chengfeng]

Hi,

https://github.com/torvalds/linux/blob/master/drivers/bus/hisi_lpc.c#L483

Our experimental static analysis tool detects a null-ptr-reference problem. It could be false positive, we report this to you just in case.

Null check is missing for the return pointer of ACPI_COMPANION at line 483 and line 504. It seems that there could be potential null-ptr-dereference problem at line 488 and line 509. Could you spare some time to have a look at it?

Thanks so much,
Chengfeng