dtls: call init_cipher() in calculate_key_block()
dtls: call init_cipher() in calculate_key_block()

init_cipher() was always called directly after calculate_key_block(),
now the call is moved into calculate_key_block().
This also moves init_cipher() in front of calculate_key_block().

Signed-off-by: Hauke Mehrtens <435ddd46dc66c007a1fa20144c823d37e0d23436@hauke-m.de>

jvermillard/tinydtls,fvdnabee/tinydtls,jvermillard/tinydtls,OlegHahm/tinydtls,spark/tinydtls,nmacs/tinydtls,OlegHahm/tinydtls,fvdnabee/tinydtls,nmacs/tinydtls,OlegHahm/tinydtls,fvdnabee/tinydtls,nmacs/tinydtls,thecodemaiden/tinydtls-fork,thecodemaiden/tinydtls-fork,spark/tinydtls,yunus/TinyDTLS-WebID,yunus/TinyDTLS-WebID,nmacs/tinydtls,spark/tinydtls,jvermillard/tinydtls,yunus/TinyDTLS-WebID,thecodemaiden/tinydtls-fork