Windows: Don't bother with pinning Kernel32.dll

We don't delay load it so it shouldn't be going anywhere.

llvm-svn: 192561
diff --git a/llvm/lib/Support/Windows/RWMutex.inc b/llvm/lib/Support/Windows/RWMutex.inc
index 7d15828..c431844 100644
--- a/llvm/lib/Support/Windows/RWMutex.inc
+++ b/llvm/lib/Support/Windows/RWMutex.inc
@@ -48,9 +48,7 @@
   if (!sChecked) {
     sChecked = true;
 
-    HMODULE hLib;
-    ::GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_PIN, L"Kernel32.dll", &hLib);
-    if (hLib) {
+    if (HMODULE hLib = ::GetModuleHandleW(L"Kernel32.dll")) {
       fpInitializeSRWLock =
         (VOID (WINAPI *)(PSRWLOCK))::GetProcAddress(hLib,
                                                "InitializeSRWLock");