staging: rtl8821ae: don't initialise statics to 0 or NULL in halbtc8192e2ant.c

Fixes all checkpatch errors reporting that statics shouldn't be initialised
to their defualt values.

Signed-off-by: Mark Einon <mark@einon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>