w32: Add missing functions qemu_mutex_destroy, qemu_cond_destroy

These functions were missing in commit
9257d46d55f1fe4e8209be9a6870e339ac3266fe.

Both functions are needed for compilations with
configuration --enable-vnc-thread.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

qemu-thread-win32.c

@@ -33,6 +33,12 @@ void qemu_mutex_init(QemuMutex *mutex)
     InitializeCriticalSection(&mutex->lock);
 }
 
+void qemu_mutex_destroy(QemuMutex *mutex)
+{
+    assert(mutex->owner == 0);
+    DeleteCriticalSection(&mutex->lock);
+}
+
 void qemu_mutex_lock(QemuMutex *mutex)
 {
     EnterCriticalSection(&mutex->lock);
@@ -80,6 +86,21 @@ void qemu_cond_init(QemuCond *cond)
     }
 }
 
+void qemu_cond_destroy(QemuCond *cond)
+{
+    BOOL result;
+    result = CloseHandle(cond->continue_event);
+    if (!result) {
+        error_exit(GetLastError(), __func__);
+    }
+    cond->continue_event = 0;
+    result = CloseHandle(cond->sema);
+    if (!result) {
+        error_exit(GetLastError(), __func__);
+    }
+    cond->sema = 0;
+}
+
 void qemu_cond_signal(QemuCond *cond)
 {
     DWORD result;