staging: rtl8723au: remove intialization of static ints

static ints are initialized to 0 by the compiler.
Explicit initialization is not necessary.

Found by checkpatch.pl - ERROR: do not initialise statics to 0 or NULL

changes made using coccinelle script:
@@
type T;
identifier var;
@@
static T var
- =0
;

Signed-off-by: Supriya Karanth <iskaranth@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>