Fix braces in e_aes.c: aes_init_key

This compiles correctly, but depending on what may be defined, it's
possible that this could fail compilation. The braces are mismatched,
and it's possible to end up with an else followed by another else.

This presumes the indentation is mostly correct and indicative of
intent. Found via static analysis.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1118)