staging: vchi: Get rid of all useless callback reasons

They are neither produced nor expected, so just delete them.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20200629150945.10720-10-nsaenzjulienne@suse.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>