headers: allow win8 path API in winstore builds

All of the entries are allowed

https://docs.microsoft.com/en-us/uwp/win32-and-com/win32-apis#apis-from-api-ms-win-core-path-l1-1-0dll
Signed-off-by: Liu Hao <lh_mouse@126.com>

mingw-w64-headers/include/pathcch.h

diff --git a/mingw-w64-headers/include/pathcch.h b/mingw-w64-headers/include/pathcch.h
index a93e739..3b02636 100644
--- a/mingw-w64-headers/include/pathcch.h
+++ b/mingw-w64-headers/include/pathcch.h
@@ -12,7 +12,7 @@
 extern "C" {
 #endif
 
-#if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_DESKTOP)
+#if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_APP)
 
 #define VOLUME_PREFIX L"\\\\?\\Volume"
 #define VOLUME_PREFIX_LEN (ARRAYSIZE (VOLUME_PREFIX) - 1)
@@ -110,7 +110,7 @@
 
 #ifdef __cplusplus
 
-#if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_DESKTOP)
+#if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_APP)
   __CRT_INLINE WINBOOL PathIsUNCEx (PWSTR path, PWSTR *pserver) {
     return PathIsUNCEx (const_cast<PCWSTR> (path), const_cast<PCWSTR *> (pserver));
   }