gameux/tests: Make test_install_uninstall_game() and _isFileExists() static.

dlls/gameux/tests/gameexplorer.c

@@ -607,7 +607,8 @@ static void test_add_remove_game(void)
         IGameExplorer_Release(ge);
     }
 }
-void test_install_uninstall_game(void)
+
+static void test_install_uninstall_game(void)
 {
     static const GUID applicationId = { 0x17A6558E, 0x60BE, 0x4078,
         { 0xB6, 0x6F, 0x9C, 0x3A, 0xDA, 0x2A, 0x32, 0xE6 }};

dlls/gameux/tests/gamestatistics.c

@@ -168,7 +168,7 @@ static HRESULT _buildStatisticsFilePath(LPCGUID guidApplicationId, LPWSTR *lpSta
  *  TRUE        file exists
  *  FALSE       file does not exist
  */
-BOOL _isFileExists(LPCWSTR lpFile)
+static BOOL _isFileExists(LPCWSTR lpFile)
 {
     HANDLE hFile = CreateFileW(lpFile, GENERIC_READ, 0, NULL,
                                OPEN_EXISTING, 0, NULL);