Added/fixed missing extern "C".

diff --git a/include/wininet.h b/include/wininet.h
index c469565..9a8da6f 100644
--- a/include/wininet.h
+++ b/include/wininet.h
@@ -1,7 +1,7 @@
 #ifndef _WINE_WININET_H_
 #define _WINE_WININET_H_
 
-#if defined(__cplusplus)
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -1399,7 +1399,7 @@
 BOOLAPI InternetCheckConnectionW(LPCWSTR lpszUrl,DWORD dwFlags,DWORD dwReserved); 
 #define InternetCheckConnection WINELIB_NAME_AW(InternetCheckConnection)
 
-#if defined(__cplusplus)
+#ifdef __cplusplus
 }
 #endif