Remove some dead code from rec_layer_s3.c

Remove some dead code from rec_layer_s3.c

It is never valid to call ssl3_read_bytes with
type == SSL3_RT_CHANGE_CIPHER_SPEC, and in fact we check for valid values
for type near the beginning of the function. Therefore this check will never
be true and can be removed.

Reviewed-by: Tim Hudson <tjh@openssl.org>