staging: rtl8192e: Remove unused variables txbytes.., txbyt.. and signa..

txbytesmulticast, txbytesbroadcast and signal_quality are initialized and
increased or set but never read. Remove dead code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/c469f82619625fecbed95532967cc7ec2b12e5f9.1674675808.git.philipp.g.hortmann@gmail.com


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