lint: fix reserved identifier in function parameter names and comments

bugprone-reserved-identifier fixes:
- gen_utils.h: rename __size parameter to 'sz' in PtrArray and PtrSizeArray
  constructors (parameter names starting with __ are reserved)

- prometheus_helpers.h: update documentation comments to reference
  '::SIZE_' instead of '::__size' to match the actual enum values

include/gen_utils.h

@@ -153,14 +153,14 @@ class PtrArray {
 	unsigned int len;
 	unsigned int size;
 	void **pdata;
-	PtrArray(unsigned int __size=0) {
+	PtrArray(unsigned int sz=0) {
 		len=0;
 		pdata=NULL;
 		size=0;
-		if (__size) {
-			expand(__size);
+		if (sz) {
+			expand(sz);
 		}
-		size=__size;
+		size=sz;
 	}
 	~PtrArray() {
 		if (pdata) ( free(pdata) );
@@ -240,7 +240,7 @@ class PtrSizeArray {
 	unsigned int len;
 	unsigned int size;
 	PtrSize_t *pdata;
-	PtrSizeArray(unsigned int __size=0);
+	PtrSizeArray(unsigned int sz=0);
 	~PtrSizeArray();
 
 	void add(void *p, unsigned int s) {

include/prometheus_helpers.h

@@ -19,7 +19,7 @@ using prometheus::Gauge;
  * @tparam map_idx_enum The enum holding the types of elements contained in the 'metrics_map' argument.
  *  This enum must contain an element '::counters'.
  * @tparam counters_enum The counters enum, holding all the identifiers of the metrics
- *  to be initialized in the 'counter_array' argument. It must contains a '::__size' element.
+ *  to be initialized in the 'counter_array' argument. It must contains a '::SIZE_' element.
  * @tparam metrics_map The type of the metrics map, it should be a 'tuple' holding the following elements:
  *  {
  *     int: metric_identifier,
@@ -77,7 +77,7 @@ void init_prometheus_counter_array(
  * @tparam map_idx_enum The enum holding the types of elements contained in the 'metrics_map' argument.
  *  This enum must contain an element '::gauges'.
  * @tparam gauges_enum The counters enum, holding all the identifiers of the metrics
- *  to be initialized in the 'gauge_array' argument. It must contains a '::__size' element.
+ *  to be initialized in the 'gauge_array' argument. It must contains a '::SIZE_' element.
  * @tparam metrics_map The type of the metrics map, it should be a 'tuple' holding the following elements:
  *  {
  *     int: metric_identifier,
@@ -135,7 +135,7 @@ void init_prometheus_gauge_array(
  * @tparam map_idx_enum The enum holding the types of elements contained in the 'metrics_map' argument.
  *  This enum must contain an element '::dyn_counters'.
  * @tparam dyn_counter_enum The counters enum, holding all the identifiers of the metrics
- *  to be initialized in the 'dyn_counter_array' argument. It must contains a '::__size' element.
+ *  to be initialized in the 'dyn_counter_array' argument. It must contains a '::SIZE_' element.
  * @tparam metrics_map The type of the metrics map, it should be a 'tuple' holding the following elements:
  *  {
  *     int: metric_identifier,
@@ -191,7 +191,7 @@ void init_prometheus_dyn_counter_array(
  * @tparam map_idx_enum The enum holding the types of elements contained in the 'metrics_map' argument.
  *  This enum must contain an element '::dyn_gauges'.
  * @tparam dyn_gauge_enum The 'dyn_gauges' enum, holding all the identifiers of the metrics
- *  to be initialized in the 'dyn_gauge_array' argument. It must contains a '::__size' element.
+ *  to be initialized in the 'dyn_gauge_array' argument. It must contains a '::SIZE_' element.
  * @tparam metrics_map The type of the metrics map, it should be a 'tuple' holding the following elements:
  *  {
  *     int: metric_identifier,