patch-tls.c introduces sm_RSA_generate_key() function used as replacement of original RSA_generate_key/RSA_generate_key_ex function.

Because of forgotten/excessive "return NULL" the function returns NULL all the times. As a result, server TLS initialisation fails and STARTTLS feature is not offered by server.

Lines
98 	+                       rsa = NULL;
99 	+               }
100 	+               return NULL;

should be

98 	+                       rsa = NULL;
99 	+               }