staging: rtl8192e: Remove unused variable rxSNRdB

rxSNRdB is initialized and set but never read. Remove dead code. Local
variable rx_snrX is then of no use. Remove rx_snrX as well. Local
variable tmp_rxsnr is then of no use. Remove tmp_rxsnr as well.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/b3150d506556375c4b155c51eabf79e128f50780.1675003608.git.philipp.g.hortmann@gmail.com


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