tls: make x25519 key generation code more similar to P256

function                                             old     new   delta
curve_x25519_compute_pubkey_and_premaster              -      74     +74
tls_handshake                                       2146    2072     -74
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 74/-74)              Total: 0 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
4 files changed