Revert "Fix return of pgws_ExecutorStart since some systems gave warnings when returning from void functions"

This reverts commit 24b2d14.

Author: Medvecrab

pg_wait_sampling.c

@@ -995,17 +995,9 @@ pgws_ExecutorStart(QueryDesc *queryDesc, int eflags)
 	if (pgws_enabled(nesting_level))
 		pgws_proc_queryids[i] = queryDesc->plannedstmt->queryId;
 	if (prev_ExecutorStart)
-#if PG_VERSION_NUM >= 180000
 		return prev_ExecutorStart(queryDesc, eflags);
-#else
-		prev_ExecutorStart(queryDesc, eflags);
-#endif
 	else
-#if PG_VERSION_NUM >= 180000
 		return standard_ExecutorStart(queryDesc, eflags);
-#else
-		standard_ExecutorStart(queryDesc, eflags);
-#endif
 }
 
 static void