Minor: Fix typos in program comments

Fix a couple of typos and writer's mistakes,
in some reference program applications
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 3e6366c..a258868 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -2168,7 +2168,7 @@
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
     /*
-     * 5. Verify the server certificate
+     * 5. Verify the client certificate
      */
     mbedtls_printf( "  . Verifying peer X.509 certificate..." );