the double/triple fault handling was not tested in user mode.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4435 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/cpu-exec.c b/cpu-exec.c
index 8d70c89..bad0805 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -354,6 +354,8 @@
                                       env->exception_is_int,
                                       env->error_code,
                                       env->exception_next_eip);
+                    /* successfully delivered */
+                    env->old_exception = -1;
 #endif
                     ret = env->exception_index;
                     break;