Fix typos & Co
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 73aefc8..db11a80 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1098,7 +1098,7 @@
         p += 48;
     }
     else
-#endif /* POLARSSL_KEY_EXCHANGE_RSA_PKS_ENABLED */
+#endif /* POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED */
 #if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED)
     if( key_ex == POLARSSL_KEY_EXCHANGE_DHE_PSK )
     {