staging: vt6656: Fix CamelCase warnings in macro

This patch fixes the checkpatch.pl warnings like:
- CHECK: Avoid CamelCase: <uVar>

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/53072a97348b08276b083ce18188b9199cbfaae6.1645477326.git.philipp.g.hortmann@gmail.com


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