Rename old_dzg_meter -> dzg_fix_negative_values

Let's use a more speaking name for what this workaround actually does,
considering that the option is now part of the public API.

examples/sml_server.c

@@ -171,7 +171,7 @@ int main(int argc, char *argv[]) {
 			exit(0); // exit here
 			break;
 		case 'd':
-			workarounds.old_dzg_meter = 1;
+			workarounds.dzg_fix_negative_values = 1;
 			break;
 		case 's':
 			sflag = true;

sml/include/sml/sml_shared.h

@@ -143,7 +143,7 @@ typedef struct {
 	 * Note that this will NOT work if a meter outputs negative
 	 * values compressed as well - but mine doesn't.
 	 */
-	unsigned int old_dzg_meter : 1;
+	unsigned int dzg_fix_negative_values : 1;
 } sml_workarounds;
 
 #ifdef __cplusplus

sml/src/sml_list.c

@@ -162,7 +162,8 @@ sml_list *sml_list_entry_parse(sml_buffer *buf, const sml_workarounds *workaroun
 	if (sml_buf_has_errors(buf))
 		goto error;
 
-	if (workarounds->old_dzg_meter && l->obj_name && l->obj_name->len == sizeof(dzg_power_name) &&
+	if (workarounds->dzg_fix_negative_values && l->obj_name &&
+		l->obj_name->len == sizeof(dzg_power_name) &&
 		memcmp(l->obj_name->str, dzg_power_name, sizeof(dzg_power_name)) == 0 && l->value &&
 		(value_len_more == 1 || value_len_more == 2 || value_len_more == 3)) {
 		l->value->type &= ~SML_TYPE_FIELD;