[PATCH v2] staging: mmal-vchiq: add a check for the return of vmalloc()

[Xiaoke Wang]

On Tue, 15 Mar 2022 16:27:38 +0100, Greg KH wrote:
> Your change just crashed the kernel :(
>
> Please be more careful

I am sorry. I ever been told that vfree(NULL) or kfree(NULL) is safe,
so I just jump to the tag `err_free` in this version.
I will resend one by adding a new proper tag.
And in fact, I did not find where ->bulk_scratch is used.

Regards,
Xiaoke Wang