crypto: x86/aes-ni - add missing error checks in XTS code

The updated XTS code fails to check the return code of skcipher_walk_virt,
which may lead to skcipher_walk_abort() or skcipher_walk_done() being called
while the walk argument is in an inconsistent state.

So check the return value after each such call, and bail on errors.

Fixes: 2481104f ("crypto: x86/aes-ni-xts - rewrite and drop indirections via glue helper")
Reported-by: Dave Hansen <dave.hansen@intel.com>
Reported-by: syzbot <syzbot+5d1bad8042a8f0e8117a@syzkaller.appspotmail.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>