staging: rtl8192e: Remove variable priv->reg_chnl_plan

Remove variable priv->reg_chnl_plan as it is only once initialized and
only once evaluated. So the result is always the same. Remove dead code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/0dd4f8eded4b172d75f0cb5d5a34ba3dc66e2e8f.1687583718.git.philipp.g.hortmann@gmail.com


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