Increase EAP server extra room for encryption overhead (for GnuTLS)

This fixes issues with some GnuTLS versions that seem to be adding
quite a bit of extra data into TLS messages. The EAP server code is
now using the same 300 byte extra room that was already used in the
EAP peer implementation.

src/eap_server/eap_tls_common.c

@@ -344,7 +344,7 @@ struct wpabuf * eap_server_tls_encrypt(struct eap_sm *sm,
 	size_t buf_len;
 
 	/* reserve some extra room for encryption overhead */
-	buf_len = plain_len + 200;
+	buf_len = plain_len + 300;
 	buf = wpabuf_alloc(buf_len);
 	if (buf == NULL)
 		return NULL;