staging: rtl8192e: Remove unchanged variable dig_enable_flag

staging: rtl8192e: Remove unchanged variable dig_enable_flag

Remove variable dig_enable_flag as its value is set to 1 at
initialization. No further writes to dig_enable_flag are done. The
equations result accordingly. Remove dead code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/24a9245840093c5a14124f9fc896433c7d85d18c.1697127817.git.philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>