staging: rtl8192e: Remove undefined function set_security

Remove function set_security as it is not defined.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/bdc9bc3a70ca2b5d86bdd2cb5c815d0b3c67972f.1683960684.git.philipp.g.hortmann@gmail.com


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