staging: rtl8192e: Remove unused variable rfAGCControl1 and rfAGCControl2

Remove unused variable rfAGCControl1 and rfAGCControl2 because they are
just once set and not used. Remove unused constants as well.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Reviewed-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/0f191930597517cf88eb6effd4c20a46c99571ad.1678569965.git.philipp.g.hortmann@gmail.com


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