staging: rtl8192e: Remove unused function rtl92e_disable_nic

Remove unused function rtl92e_disable_nic to shorten code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/5ce2ef58f66e25d7db7432c56c7b7c37a2b15fc1.1681627603.git.philipp.g.hortmann@gmail.com


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