x86: svm: Always clear event_inj on vmexit

We currently only clear SVM_EVTINJ_VALID after successful interrupt
delivery. This apparently does not match real hardware which clears the
whole event_inj field on every vmexit, including unsuccessful interrupt
delivery.

Reported-by: Erik van der Kouwe <vdkouwe@cs.vu.nl>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

target-i386/op_helper.c

diff --git a/target-i386/op_helper.c b/target-i386/op_helper.c
index c1256f4..71331c6 100644
--- a/target-i386/op_helper.c
+++ b/target-i386/op_helper.c
@@ -5388,6 +5388,7 @@
              ldl_phys(env->vm_vmcb + offsetof(struct vmcb, control.event_inj)));
     stl_phys(env->vm_vmcb + offsetof(struct vmcb, control.exit_int_info_err),
              ldl_phys(env->vm_vmcb + offsetof(struct vmcb, control.event_inj_err)));
+    stl_phys(env->vm_vmcb + offsetof(struct vmcb, control.event_inj), 0);
 
     env->hflags2 &= ~HF2_GIF_MASK;
     /* FIXME: Resets the current ASID register to zero (host ASID). */