mssign32: Implement SignerFreeSignerContext.

dlls/mssign32/mssign32.spec

@@ -22,7 +22,7 @@
 @ stub SignerAddTimeStampResponse
 @ stub SignerAddTimeStampResponseEx
 @ stub SignerCreateTimeStampRequest
-@ stub SignerFreeSignerContext
+@ stdcall SignerFreeSignerContext(ptr)
 @ stub SignerSign
 @ stdcall SignerSignEx(long ptr ptr ptr ptr wstr ptr ptr ptr)
 @ stub SignerTimeStamp

dlls/mssign32/mssign32_main.c

@@ -27,6 +27,7 @@
 #include "wincrypt.h"
 
 #include "wine/debug.h"
+#include "wine/heap.h"
 
 #include "mssign32_private.h"
 
@@ -84,3 +85,9 @@ HRESULT WINAPI SignerSignEx(DWORD flags, SIGNER_SUBJECT_INFO *subject_info, SIGN
                     wine_dbgstr_w(http_time_stamp), request, sip_data, signer_cert);
     return E_NOTIMPL;
 }
+
+HRESULT WINAPI SignerFreeSignerContext(SIGNER_CONTEXT *signer_context)
+{
+    heap_free(signer_context);
+    return S_OK;
+}