staging: vt6655: fix camelcase in pbyCxtBuf

Replace camel case variable name for variable pbyCxtBuf
with snake case equivalent, in mac.h

Signed-off-by: Tommaso Merciai <tomm.merciai@gmail.com>
Link: https://lore.kernel.org/r/20211001202504.410383-1-tomm.merciai@gmail.com


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