crypto: gcm - fix rfc4543 to handle async crypto correctly

commit d733ac90f9fe8ac284e523f9920b507555b12f6d upstream.

If the gcm cipher used by rfc4543 does not complete request immediately,
the authentication tag is not copied to destination buffer. Patch adds
correct async logic for this case.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc crypto/gcm.c
Simple merge