crypto/mem.c: check the alignment for being a power of 2 in CRYPTO_aligned_alloc

crypto/mem.c: check the alignment for being a power of 2 in CRYPTO_aligned_alloc

Otherwise the roundup calculation performed in the open-coded implementation
may put the pointer out of bounds.

Signed-off-by: Eugene Syromiatnikov <esyr@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28059)