Never checked NULL pointer in drivers/media/v4l2-core/videobuf-core.c

[Shaobo He <shaobo@xxxxxxxxxxx>]

Hello everyone,

I found that macro `CALLPTR` in drivers/media/v4l2-core/videobuf-core.c can 
evaluate to NULL yet all its usages (__videobuf_copy_to_user, 
__videobuf_copy_stream) are never NULL checked. I doubt but am not completely 
sure that use cases of the CALLPTR macro can accept NULL pointers. Please let me 
know if it makes sense or not.

Best,
Shaobo