cyassl: Fix library initialization return value

(Curl_cyassl_init)
- Return 1 on success, 0 in failure.

Prior to this change the fail path returned an incorrect value and the
evaluation to determine whether CyaSSL_Init had succeeded was incorrect.
Ironically that combined with the way curl_global_init tests SSL library
initialization (!Curl_ssl_init()) meant that CyaSSL having been
successfully initialized would be seen as that even though the code path
and return value in Curl_cyassl_init were wrong.