fltmgr.sys: Use wide-char string literals.

dlls/fltmgr.sys/main.c

@@ -82,8 +82,7 @@ void WINAPI FltUnregisterFilter( PFLT_FILTER filter )
 
 void* WINAPI FltGetRoutineAddress(LPCSTR name)
 {
-    static const WCHAR fltmgrW[] = {'f','l','t','m','g','r','.','s','y','s',0};
-    HMODULE mod = GetModuleHandleW(fltmgrW);
+    HMODULE mod = GetModuleHandleW(L"fltmgr.sys");
     void *func;
 
     func = GetProcAddress(mod, name);