src: fix inconsistency in extern declaration

NodeCounterProvider is declared as extern but defined as EXTERN_C.
This confuses clang-cl.

PR-URL: #20436
Refs: #19630
Reviewed-By: Tiancheng "Timothy" Gu <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Refael Ackermann <[email protected]>
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Tobias Nießen <[email protected]>

src/node_win32_perfctr_provider.cc

@@ -119,7 +119,7 @@ PPERF_COUNTERSET_INSTANCE perfctr_instance;
 namespace node {
 
 
-EXTERN_C DECLSPEC_SELECTANY HANDLE NodeCounterProvider = nullptr;
+HANDLE NodeCounterProvider = nullptr;
 
 void InitPerfCountersWin32() {
   ULONG status;