staging: rtl8712: use shorter array initializations

Use empty brace syntax to initialize zero valued arrays.
Simplifies and shortens the code a little bit.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200919085032.32453-2-straube.linux@gmail.com


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