x86/HVM: don't inject #DB with error code

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper@citrix.com>
master commit: 057e0e72d2
master date: 2015-11-12 16:59:18 +0100

xen/arch/x86/hvm/hvm.c

@@ -3843,7 +3843,7 @@ void hvm_task_switch(
         goto out;
 
     if ( (tss.trace & 1) && !exn_raised )
-        hvm_inject_hw_exception(TRAP_debug, tss_sel & 0xfff8);
+        hvm_inject_hw_exception(TRAP_debug, HVM_DELIVER_NO_ERROR_CODE);
 
     tr.attr.fields.type = 0xb; /* busy 32-bit tss */
     hvm_set_segment_register(v, x86_seg_tr, &tr);