Actually reset the context on save as advertised

Also fix some wording in the documentation while at it.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 8d75cf3..60e9ab0 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -11522,7 +11522,7 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 4, "saved context", buf, used );
 
-    return( 0 );
+    return( ssl_session_reset_int( ssl, 0 ) );
 }
 
 /*