staging: rtl8192e: Rename variable Bandwidth to avoid CamelCase

Rename variable Bandwidth to bandwidth to avoid CamelCase
which is not accepted by checkpatch.pl .

Signed-off-by: Yogesh Hegde <yogi.kernel@gmail.com>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/20220928180350.GA82748@zephyrus


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