Delete leftover code

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index ad794e6..429d124 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -159,7 +159,6 @@
             return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
         }
 
-        //hash_len = mbedtls_md_get_size( md );
         hash_len = PSA_HASH_LENGTH( alg );
 
         if( hash_len == 0 )