crypto: tcrypt - avoid signed overflow in byte count

The signed long type used for printing the number of bytes processed in
tcrypt benchmarks limits the range to -/+ 2 GiB, which is not sufficient
to cover the performance of common accelerated ciphers such as AES-NI
when benchmarked with sec=1. So switch to u64 instead.

While at it, fix up a missing printk->pr_cont conversion in the AEAD
benchmark.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>