staging: rtl8712: r8712_aes_decrypt(): Change return type

Change return type of r8712_aes_decrypt from u8 to void as its return
value is never checked. Modify return statements accordingly.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190802064212.30476-9-nishkadg.linux@gmail.com


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