staging: rtl8712: Remove variable xcnt

The variable xcnt being incremented but it is never referenced,
it is redundant and can be removed.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20221021180950.29139-1-colin.i.king@gmail.com


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