dinput: Fix a memory leak

[Andrew Talbot]

Changelog:
    dinput: Fix a memory leak.

diff --git a/dlls/dinput/dinput_main.c b/dlls/dinput/dinput_main.c
index 15f3cda..fdb92ea 100644
--- a/dlls/dinput/dinput_main.c
+++ b/dlls/dinput/dinput_main.c
@@ -149,6 +149,7 @@ HRESULT WINAPI DirectInputCreateEx(
     if (!check_hook_thread())
     {
         IUnknown_Release( (LPDIRECTINPUT7A)This );
+        HeapFree(GetProcessHeap(), 0, This);
         return DIERR_GENERIC;
     }