unbreak windows build

windows msvc toolchain with werror and wconversion
will break if converting long to DWORD.

Author: 741g

googletest/src/gtest.cc

@@ -1691,7 +1691,7 @@ AssertionResult HRESULTFailureHelper(const char* expr,
   char error_text[kBufSize] = { '\0' };
   DWORD message_length = ::FormatMessageA(kFlags,
                                           0,   // no source, we're asking system
-                                          hr,  // the error
+                                          static_cast<DWORD>(hr),  // the error
                                           0,   // no line width restrictions
                                           error_text,  // output buffer
                                           kBufSize,    // buf size