fix comments issues

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 6b0bf57..b1f5f36 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1412,14 +1412,14 @@
 }
 
 /*
- * Write tls13 handshake message header
+ * Write TLS 1.3 handshake message header
  */
 int mbedtls_ssl_tls13_start_handshake_msg( mbedtls_ssl_context *ssl,
                                            unsigned hs_type,
                                            unsigned char **buf,
                                            size_t *buflen );
 /*
- * Write tls13 handshake message tail
+ * Write TLS 1.3 handshake message tail
  */
 int mbedtls_ssl_tls13_finish_handshake_msg( mbedtls_ssl_context *ssl,
                                             size_t buf_len,
@@ -1433,7 +1433,7 @@
 
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 /*
- * Write TLS1.3 Signature Algorithm extesion
+ * Write TLS 1.3 Signature Algorithm extension
  */
 int mbedtls_ssl_tls13_write_sig_alg_ext( mbedtls_ssl_context *ssl,
                                          unsigned char *buf,