Fix missing return value checks

Ensure that all functions have their return values checked where
appropriate. This covers all functions defined and called from within
libssl.

Reviewed-by: Richard Levitte <levitte@openssl.org>

ssl/s3_lib.c

@@ -3114,7 +3114,8 @@ int ssl3_new(SSL *s)
     s->s3 = s3;
 
 #ifndef OPENSSL_NO_SRP
-    SSL_SRP_CTX_init(s);
+    if(!SSL_SRP_CTX_init(s))
+          goto err;
 #endif
     s->method->ssl_clear(s);
     return (1);